What's the grammatical logic of emphatic phrases like "I do eat sushi"?

Question

Let's consider, for example, this excerpt from a poem by Grenfell:

Those ancient Jew boys went like stinks,

They knew not reck nor fear,

Old Noah knocked the first two jinks,

And Nimrod got the spear.

And ever since those times of yore

True men do ride the fighting boar.

The last line here contains two verbs—do and ride—and I know that do here is used to make the phrase emphatic.

What I'm curious about is the underlying logic of such emphatic constructions. As a non-native speaker, I find it difficult to see how it makes any sense to use a transitive verb, do, right before another verb, ride. How can a verb be an object? Or should I see ride here as a noun rather than a verb?

What makes me even more curious is that the German language, which belongs to the same branch of languages, doesn't have any similar construction, so it must be something unique to English. (Update: A comment below says that there's a German equivalent that uses tun and is a feature of several dialects and minority languages in Germany.)

My question: What exactly is the logic of using do to make phrases emphatic?

Answer 1

This is an idiomatic turn of speech that has probably come about as an evolution from certain related usages. The following explanation is mine and seems quite plausible although details might have to be changed or added. (bolded text and square brackets due to user LPH)

(SOED) 29 As a substitute for a verb just used.
a v.i. replacing a verb and its object (if any) in affirmatives and in imperatives conveying assent to a request or suggestion OE [from Old English, that is roughly from 700 to 1100]
♦ J. COLLINS We pay double the price we formerly did.
♦ G. B. SHAW Lady Farwaters May I try to explain? The Clergyman Please, do.
b v. i. & t. (w. it) Replacing a verb with as, it, so or which referring to the earlier verb or clause. OE
♦ W. CRUISE Whoever wanted to surrender must .. do it in person.
♦ S.T. WARNER He told them to go away, he even begged them to do so.
c v. t. & i. Replacing a verb and taking its construction(s) ME [that is within the period "1150-1349"]
♦ GOLDSMITH I .. chose my wife, as she did her wedding-gown[, for qualities that would wear well].
d v.i. Replacing a verb in an emphatic repetition. L16 [that is within the period "1570-1599"]
♦ P. BEER He rang me up In a dream, My brother did.
♦ D.L. SAYERS 'Ev another crumpet, do, Mr. Bunter.
30 As a periphrastic auxiliary in past and present tenses.
a Now arch. & dial.
b In affirmative sentences with inverted word order. OE
♦ J. CONRAD More than any other event does 'stranding' give to the sailor a sense of .. failure.
c In questions and negations […] LME [1350-1469]

We now come to the usage that concerns the question, that is, still as an auxiliary verb, but in the context of an affirmative verb and associated to it by juxtaposition.

(SOED) 30 d In affirmative sentences, used to give emphasis, esp. in contrast with what precedes or follows. L16
♦ T. HARDY At last a packet did indeed arrive at the village.
♦ S. SPENDER The Dents du Midi do look incredibly like teeth.
♦ R. P. JHABVALA For all she was so thin and white, she did look tough.

Most likely, the idea of associating emphasis with the use of a preceding "do" came about as a slow progression from the usage of "do" as
i replacement for a verb (29 a OE, b OE, c ME, d L16), then as
ii support in non-assertive context (30 b LME), then as
iii replacement with emphatic repetition (29 d L16), and finally as
iv emphasis through addition to the verb as an auxiliary (30 d L16).

There is no logic solely inherent to the final construction associated with "iv" that could possibly be reckoned with as endowing it with the power of communicating emphasis. The emphasis that is felt by a user of the language in relation to this turn is merely the result, as time went by, of the preservation through the agency of two processes, of the fact that emphasis is meant, the first process being the use of the construction in contexts where emphasis was needed, and the second being the teaching that emphasis is its purpose. How the fact came into being is a matter of quantum leaps that took place in the minds of users in ages gone by.

The idea that the word "do" is a replacement for a verb, evidently, gives it the force of that verb. The quantum leap that takes place in passing to the use of the verb for non-assertive context is one where can be seen a weakening of its function as a replacing term, where the word gets back something of its general meaning, although not on the level of pure semantics since an auxiliary is not a content verb.

It can be inferred that probably the next leap occurs as a passage from"ii" to "iii", although the first occurrences of "iii" and "iv" are contemporaneous for the purpose of historical information to the general user; this seems to be so because "iii" comprises a function of replacement that is totally absent in "iv", but is obviously inherited. The idea of emphasis has now found its way in the semantic of the word in association to a particular syntax (affirmative statements, imperatives, see examples). In consequence of the fact that the idea that naturally repetition is associated sometimes with insistence, and of the fact that the word "do" is already conceived for repetition, the addition of a notion of emphasis to this word seems a process straightforward enough, but there exists still an unknow as to the exact unfolding of this addition.

A last leap has finally taken place that seems to have occurred through the perception of a possible economical use of terms that made certain repetitions useless, therefore the resulting emphasis without the function of repetition (that was immediately lost).

Answer 2

Do is functioning as an auxiliary verb, like can or may, and it expresses something more for the clause that follows it, like emphasis (do) or modality (may) ("Auxiliary verb," Wikipedia). As other commenters note, it is not transitive as an auxiliary verb and does not take an object like a transitive verb does. Here, it adds emphasis to the following clause.

Under what logic does the poem use do?

One answer is scansion. Grenfell is writing lines of iambic tetrameter (four iambs, or unstressed-stressed syllables) and iambic trimeter (three iambs). I'll separate feet with vertical lines and star the stresses:

Those *an* | cient *Jew* | boys *went* | like *stinks*,

They *knew* | not *reck* | nor *fear*,

Old *No* | ah *knocked* | the *first* | two *jinks*,

And *Nim* | rod *got* | the *spear*.

And *ev* | er *since* | those *times* | of *yore*

True *men* | do *ride* | the *fight* | ing *boar*.

Without do, the second iamb doesn't come together. Do adds an unstressed syllable, allows ride to serve as a stressed syllable in the iamb, and the line scans.

Another answer is that it emphasizes the final verb phrase in the stanza over the others. The emphasis isn't on what Noah or Nimrod did; the emphasis is instead on what "true men" do "ever since": "True men do ride the fighting boar." It's the syntactic equivalent of thumping the table loudly for emphasis.

Answer 3

do has a strengthening, emphasizing function in these constructions.

It can be understood as an auxiliary. From that perspective, the emphasis is rooted in the contrast to two constructions which would weaken or even negate the assertion of the sentence: The auxiliary do is used when negating the assertion, and when turning the assertion into a question. By contrast, the presence of do in the non-negated, non-questioned sentence strengthens the assertion.

From the perspective of paradigmatic analysis, do could also be seen as a kind of modal verb here, emphasizing that the mood of the sentence is indicative and the tense is present.

Marking Absence of Negation

First, its structure marks the absence of the negation. Compare the three sentences:

• P1) I eat sushi.
• P2) I do eat sushi.
• N) I do not eat sushi.

The positive statements P1 and P2 both have the same meaning. But the structure of P2 is in close analogy to N. This analogy puts additional emphasis on the difference - the negation particle not is present in N, but it is not present in P2. That is why P2 has a stronger emphasis on the positivity of the statement.

Reasserting Answer to an Implied Question

Second, the sentence structure with the auxiliary do mirrors the sentence structure of a question:

• Q) Do I eat sushi?
• A) I do eat sushi.

Calling the assertion into question is a means of weakening it. By contrast, the presence of do makes A) appear as an answer to an implied question Q), a reassertion. This is also strengthening emphasis.

Paradigmatic Perspective: Contrasting Modal Verbs and Temporal Auxiliaries

The following is an analysis from a paradigmatic perspective. The term paradigm is referring to the term as it was introduced by Ferdinand de Saussure here. To summarize Saussure very roughly: Paradigmatic analysis determines the meaning of a linguistic unit (such as a word) by asking "What could be in the position of that word instead?". Thus, paradigmatic analysis often works with substitution tests.

Applied to to our topic: If we want to see what do means in these constructions, we may ask "What could be in the position of do that is not there?" As do is not mandatory from a grammar point of view (the sentence I eat sushi is grammatical), the presence of do marks the absence of the other paradigmatic options.

Compare the sentences in the following (non-exhaustive) list of examples of modal verbs:

• O1) I must eat sushi
• O2) I have to eat sushi.
• P) I may eat sushi.
• Po1) I could eat sushi.
• Po2) I might eat sushi.

O1 and O2 express obligation, P expresses permission, Po1 and Po2 both express some sort of possibility.

In contrast to these,

• A) I do eat sushi.

expresses the modality of actuality.

Similarly, in contrast to sentences which are temporally marked,

• F1) I will eat sushi.
• F2) I am going to eat sushi.

the sentence with do stresses the present tense of the sentence. As present is not just used to express that something which is happening "now", but also to express certainty or the rule-character of the sentence, this also results in an emphasis.

Answer 4

You can explain it using this theory.

1. In an English sentence, there is always an AUX (auxiliary verb) element: S AUX V.

2. In some common sentences, like "I eat sushi", the AUX is invisible though "I Ø eat sushi".

3. In some situations the Ø auxiliary is replaced by the visible word do.

One example is the subject-aux inversion when a question is formed.

Subject-aux inversion with visible auxiliary:

You have eaten sushi. → Have you eaten sushi?

Subject-aux inversion with invisible auxiliary:

You Ø eat sushi. → Ø you eat sushi? → Do you eat sushi?

Here, a rule applies that Ø cannot be at the start of the clause. If Ø is moved to the start, it becomes visible as do.

So then in emphasis, some similar rule is playing out. In English, emphasis is added to a word with stress: some word or syllable is spoken more loudly and with a higher pitch.

Given the sentence "I Ø eat sushi", we can place stress on I, eat, or sushi. But none of those choices express the desired semantics. Emphasizing eat means "I eat sushi (as opposed to some other action, like just staring at it)."

The emphasis "I eat sushi (as opposed to not eating it)", cannot be expressed by emphasizing any of the visible words in the sentence. Therefore, a helpful mechanism comes into play: the invisible Ø auxiliary gets replaced by a visible do, and that takes the emphasis, such the action "eat" remains unquestionably given.

Note that the negative of the sentence would be "I don't eat sushi", and in that sentence, emphasis on don't would be used to clarify the not eating. "I don't eat sushi (in case you misunderstood, thinking that I do.)" The do appears in the same place as do not, by analogy to the negative sentence.

The Do support Wikipedia page is dedicated to the topic of the do auxiliary being inserted into sentences. It doesn't talk about the empty auxiliary hypothesis, but you can see that some of it is hinting at it:

Do-support is not used when there is already an auxiliary or copular verb present or with non-finite verb forms (infinitives and participles).

The empty auxiliary concept streamlines the idea while capturing this exclusion. I.e. do-support doesn't occur when there is an auxiliary because the empty space is already filled.

The page also notes:

Furthermore, the use of do as an auxiliary should be distinguished from the use of do as a normal lexical verb, as in They do their homework.

Correct, and in relation to the topic of this question, the following is possible:

I do do my homework!

In other words, how we can see it is that "I Ø do my homework" has an empty auxiliary, a regular verb do, allowing for do-support for this emphatic case.

This section of the page discusses the do auxiliary used for emphasis. The page doesn't discuss anything resembling the empty auxiliary hypothesis. A reference to it occurs in a comment on the talk page of that page. Someone mentions:

Freidin, Robert (1982). Foundations of Generative Syntax. MIT Press. p. 171. "The distribution of this auxiliary can be accounted for via a substituion transformation that inserts the auxiliary do (not to be confused with the verb do) into an empty auxiliary position in Infl."

Answer 5

What's the grammatical logic of emphatic phrases like "I do eat sushi"?

To understand this, we need to think about constructions. And we also need to think about the fact that languages like English (as opposed to sign languages, for example) involve sound, even when written.

To appreciate this last point consider the following examples:

1. plate, weight
2. though, tough

Even though you read the examples above as black squiggles on your screen, you'll notice that the examples in (1) rhyme. And the examples in (2), which look the same don't. The reason is that the sounds in (1) are similar, but the sounds in (2) aren't.

English has a class of verbs which have certain syntactic properties, known 'auxiliary verbs'. These properties do not involve preceding another verb, but rather properties like being necessary for sentential negation, the ability to contract with not (or having negative inflections, if you prefer), the ability to invert with subjects in certain constructions and so forth.

English has a construction, or actually a family of closely related constructions, which emphasise the positive or negative polarity of the sentences they occur in. These usually contrast with an idea of the opposite polarity, often previously mentioned. Here are a couple of examples of such constructions:

• A: You can't make sushi
• B: I can make sushi! / I can too make sushi!

The interesting thing about these three constructions is that they all require an auxiliary verb and they all require stress on the auxiliary verb. Here's what happens if there's no auxiliary:

• A: You don't make sushi.
• B1: ^? I make sushi! (Contrasts making with, for example, buying or eating)
• B2: *I make too sushi! (ungrammatical)

Two particular tensed constructions in English don't use auxiliary verbs: the present simple and past simple. When these constructions combine with other constructions that require auxiliary verbs, there is a special come-to-the-rescue verb, auxiliary do, sometimes known as 'supportive do* or dummy do:

• *I like not cheese. [ungrammatical in modern English]
• I do not like cheese.
• *You like cheese, like you? [ungrammatical]
• You like cheese, do you?
• *Yes, I like cheese. [ungrammatical]
• Yes, I do like cheese.
• I like [too] cheese. [not positive polarity emphatic].
• I do [too] like cheese.

The reasons that other languages do not need a support verb like do in positive polarity emphatic sentences may be any of the following (plus several others):

• they do not have a class of syntactically distinguishable auxiliary verbs
• they always have auxiliary verbs and don't need a support verb
• they don't have emphatic constructions which require auxiliary verbs

The Julian Grenfell poem

This poem is the early twentieth-century version of Meatloaf's A Bat Out of Hell. It's a teenager's paean on maleness and virility, although unlike the Meatloaf version, with a hint of homoeroticism. There's a crucial difference, however, which we'll come to later. Here's the first and last verses of Hymn To The Wild Boar:

God gave the horse for man to ride
And steel wherewith to fight,
And wine to swell his soul with pride
And women for delight:
But a better gift than these all four
Was when He made the fighting boar.

...

Those ancient Jew boys went like stinks,
They knew not reck nor fear,
Noah knocked the first two jinks,
And Nimrod got the spear.
And ever since those times of yore
True men do ride the fighting boar.

The crucial difference between Hymn to the Wild Boar and Meatloaf's A Bat Out of Hell is that the former is the kind of thing that Boris Johnson the Oxford classicist would write if trying to emulate the teenage male virility of A Bat Out of Hell. Whilst Grenfell uses current and trendy (World War One) terminology like stink, and has stretches like God gave ... women for delight, it also uses archaic vocabulary and phrasing to make it grandiose and evocative of classic sagas (as Boris Johnson would approve of). In terms of vocabulary there are archaic terms like reck, and in terms of grammar there are uses, for example, of unstressed declarative periphrastic do, which I'll now explain.

In early sixteenth-century English, it was common to use auxiliary do in sentences using the present simple, where you could also instead just use the present tense form of the lexical/main verb. The examples in the following pairs were, therefore, exchangeable with no change of meaning:

• Loved Tom the woman? / Did Tom love the woman?
• I loved not the woman / I did not love the woman.
• I loved the woman / I did love the woman.

In the last, declarative examples, there was no difference in meaning regardless of the presence or absence of do, and the word do was typically unstressed.

By the eighteenth century, however, do in declarative sentences had become part of an emphatic construction as it still is today.

Grenfell's poem uses do in a line where, because of the metre of the poem, it clearly is not stressed. This is an archaic use of unstressed periphrastic declarative do which makes the poem seem older, grander and more classical than it really is.