Which of these phrases is more correct?

The man who I know to be unhappy

The man whom I know to be unhappy

Is one of the verbs in the phrase more important, thus determining the noun case, or is something else happening with the particular combination of verbs? (The man whom I know is valid but the man to be unhappy isn't; the tense must be specified as in the man who is unhappy.)

  • 2
    At first I thought this would be about constructions like "The man who jumped in the river and a shark attacked is now well on his road to recovery," where "jumped" wants "who" and "attacked" wants "whom". But in the example, there's only one relevant verb: "know". Sep 2, 2011 at 14:15
  • The answer here is that "whom" is right but "who" is acceptable, but as I always say, when in doubt use "who". Avoid "whom" unless you're very sure. Sep 2, 2011 at 15:59

10 Answers 10


In this instance, the pronoun "who" is the object of the verb "know". So you want to use objective case whom.


The quantity of verbs has no effect on the choice between who and whom. The only thing you need to figure out is whether or not you need a subject for a verb.

If who/whom is the subject of a verb, use who. Otherwise, use whom.

The non-technical instruction on choosing the right word: Who can only be used as a subject, so if you don’t need a subject, don’t use who; use whom.

For this example, the correct choice is whom. “The man who/whom I know to be unhappy…” I suppose this is followed by a verb. The simple subject of the sentence (of the verb that follows) is man, not who/whom. Who/whom is not the subject of a verb, so you use whom.

Another way to write the example, which might make it easier to parse, is as follows: “The man, whom I know is unhappy,…” As we see, whom is not serving as the subject of any verb.

Source: Precise Edit

  • 3
    Er, this isn't exactly correct. "The man, whom I know to be unhappy,..."; fine, we all agree there. But "the man, who[m] I know is unhappy,..." seems to have is as a main verb, in which case the pronoun is "who". Aug 14, 2011 at 21:51
  • @TimLymington The relevant question is whether who[m] is the subject of the verb in the subordinate clause. "The man whom I know is unhappy" has "The man" (np) as the subject of the verb "is" in the main clause. Who[m] only appears in the subordinate clause ("whom I know"), where it's pretty obvious that the verb is "know" and the subject is "I". Sep 1, 2011 at 15:59
  • Returning to the original example, the whole thing is a noun phrase: "The man, whom I know to be unhappy, ...". The next thing should be the (transitive) verb of the main clause. The subordinate clause is "whom I know to be unhappy", and the subject of the verb "know" is "I", while "to be" is an infinitive with no subject (it's dependent on "know"). "Who[m]" is not a subject, so it's "whom", not "who". Sep 1, 2011 at 16:02
  • 1
    @Richard: what would you say about "the man who[m], I know, is unhappy,..."? It's still a subordinate clause, but it's clearly who. Sep 1, 2011 at 21:23
  • @TimLymington, no, that's whom too. "The man who knows me" is the classic who. Sep 1, 2011 at 22:00

As I write, all other answers agree that whom is the correct choice in this construction (because "whom I know to be unhappy" is an auxiliary phrase, wherein whom is not the subject of a verb).

I don't dispute the strict grammatical position, but I would say that, as suggested by this NGram, whom appears to be increasingly falling into disuse.

enter image description here

Correspondingly, here are over 1000 written instances of "who I know to", most if not all of which are "incorrect" according to strict grammar. In my opinion, whom is already becoming somewhat 'dated', and it's only a matter of time before it disappears completely.

  • 1
    This is a very good and succinct answer. In my experience "who" for "whom" is one of the five or six crucial markers of difference between informal, speech-mimicking writing and formal or traditional writing. (I won't bore you with the others.) I agree with you completely than whom is rapidly going the way of shall, at least in U.S. English.
    – Sven Yargs
    May 12, 2015 at 21:08
  • @Sven: Yeah - by nature I'm inclined to stick two fingers up to "formal or traditional" constraints. But you can't fight City Hall if they think you're an oik whom don't know basic grammar! :) May 12, 2015 at 23:32
  • {I wrote 'than' for 'that' in my comment, and now it's too late to fix it. Arg. But...) I want to ask you about 'oik'. It's not used in U.S. English, but it's a great term. The horribly unreliable Urban Dictionary dates it to 1925 and connects it to hoick meaning "spit" (U.S. English has hock meaning something similar). Is that your understanding of the term? Does it have any relation to the "oi" movement of the late '70s/early '80s as a term linked to British working-class youth? Maybe this should be an EL&U question. Anyway, good word choice by you.
    – Sven Yargs
    May 12, 2015 at 23:52
  • 1
    @Sven: I didn't even know about "the 'oi' movement of the late 70s" until just now. I recall that in the 60s we kids were fond of chanting Oggy oggy oggy! Oi Oi Oi! in various contexts - particularly, to express solidarity between two separate by nearby groups (scouts who happened to be camping in adjacent fields, for example, since it's essentially a "lead-response" type chant). You still hear it sometimes at football grounds. I always thought Oi! there was "peasant-speak" for Aye! Yes! I'm here!, but OED just says "origin unknown". May 13, 2015 at 11:49
  • 1
    ...actually, although I've used oik many times over the years in speech, I've so rarely seen it written down I had to do a quick check in Google Books to see how it's spelled before I wrote it here. GB made it pretty clear almost everyone spells it without a c, so I was gratified today to see that OED's first three citations all spell it oick (some vague recollection of which is presumably why I was uncertain about the written form myself). As you say, it's a neat usage, so I figure I have to do my bit to keep oik = lout, yob in circulation! :) May 13, 2015 at 11:58

As the question is tagged with acceptability, I will report the following paragraph, reported by NOAD in the usage of who section:

The normal practice in modern English is to use who instead of whom (Who do you think we should support?) and, where applicable, to put the preposition at the end of the sentence (Who do you wish to speak to?). Such uses are today broadly accepted in standard English, but in formal writing it is best to maintain the distinction.

If you want to avoid writing who when you should use whom (or vice versa), you can use that.

the man that I know to be unhappy

That is a relative pronoun used to introduce a defining or restrictive clause, especially one essential to identification; it is used instead of when, which, who, whom.

the book that I have bought yesterday
the person that I will meet tomorrow
the year that Anna was born

  • 1
    hmm. I read the question as having more to do with the proper case of who/whom? Isn't it about what role it plays in the clause?
    – jlembke
    Jan 27, 2011 at 6:03

"I know the man to be unhappy" seems be more informative, but it doesn't answer the question until you change it again to "Him I know to be unhappy". Or how about "I know that man [him] to be unhappy. This would indicate that you want the objective case - whom.


The main verb in your question is "know", so it is "The man whom I know to be unhappy", just as it is "The man whom I know".

It gets more complex if you replace 'to be' with 'is', as there are several possible meanings. "The man who, I know, is unhappy" is equivalent to "The man who is unhappy (I know it)", so whom would be wrong. "The man, whom I know, is unhappy" = "The man is unhappy: I know him (not he). Without any commas, or (just as wrong) with a single comma after 'know', ambiguity makes it impossible to say what the pronoun should be (unless the rest of the sentence makes it clear). Moral: punctuation is important, and don't lazily cut "to be" down to "is" unless you are clear about how you are changing the meaning.

NB Precise Edit's answer (quoted by Lauren), leaves out all the commas in this phrase, so isn't helpful.


To answer the direct question ...

Verb clauses can be nested and are parsed from the inner most to the outermost. so "I know 'x to be" is a verb clause which after being parsed would resolve effectively to "is" and therefore your second statement is true - it the correct stereotype verb clause would be "the man who is unhappy".

The response to the other comment - I don't know if this a culture thing but I do not find it to be correct usage to replace who with that. That can only be used when talking about NOT-people.

  • But it is "I know him to be unhappy" not "I know he to be unhappy".
    – Kosmonaut
    Feb 23, 2011 at 2:37
  • Maybe it's a culture thing. I don't see any problem with using "that" for a person; as exemplified by @kiamlaluno's answer.
    – user16269
    Jan 19, 2012 at 9:53

Very simple. MAN is the subject of the main clause. The VERB of the main clause is IS. (This man is unhappy). "who I know" is a subordinate adjective clause modifying MAN. The person speaking knows the man. The subject of the subordinate clause is I. The verb is KNOW. WHOM is what we call the subordinate clause marker, but it is also the presumed object of the verb KNOW, so it takes the objective (Whom) case, not the subjective. When pronouns follow a TO BE verb, and refer back to the subject of the sentence, they take the SUBJECTIVE case. (I am HE. She is WHO?) Most of the time, one's ear tells one what word to use.

  • My ear says 'the man whom ...? avoid' And I've been to a university you'll have heard of. Sep 6, 2020 at 15:04

We say
'The man who is unhappy'
'The man whom I know to be unhappy'

Because in the first example 'is' is the verb, in the second 'know' is the verb. In the first, 'the man' is the subject to 'is'. In the second, 'the man' is the object to 'know'.

  • Hello, Salwa. No, we (or at least 95%+ of us) don't say 'The man whom I know to be unhappy' any more. Fifty years ago in the public-school-educated section of the English-speaking world, yes. Sep 6, 2020 at 15:01

The man who I know is unhappy. 'is unhappy' is a clause and the object of the verb 'know' every clause needs a subject. The verb 'is' in the clause needs a subject and every subject must be in the subjective case. So, the subjects in this sentence are I, the man or he, and who. 'is' needs a subject and 'who' should take the place of the man or he. Whom is wrong and can not be subject of 'is'. To solve the problems in this sentence, every verb in the sentence must have a subject. So, 'who' is the perfect subject for the linking verb 'is'.

  • The original post doesn't use "is unhappy": it asks about "The man who I know to be unhappy" vs. "The man whom I know to be unhappy".
    – herisson
    Apr 24, 2018 at 16:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.