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  • I want to see you.
  • I look forward to seeing you.

How can one say "to" in the first sentence is an infinitive marker and in the second sentence a preposition when we are given just the following two sentences and are asked to fill in the blanks?

  • I want to ____(see/seeing) you.
  • I look forward to __(see/seeing) you.
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Sorry, we're not responsible for the silliness of many English teachers and tests, worldwide. It's a matter of learning which complementizers each verb takes, and which constructions each one allows, requires, or forbids. An example, with a couple of answered problems, is here, if you want details. – John Lawler Feb 9 '13 at 17:13
In simple words, "to" is a preposition when followed by a noun and an infinitive-marker when followed by an infinitive. – rogermue Nov 2 '14 at 15:07

Having written this, I've just noticed Barrie's answer. By far the easiest thing to do is to learn the constructions, but they can be analysed (as Bill Franke asked in a comment). Whether it's actually worth the effort may be a moot point.

Let's deal with the second sentence first, because that's easier.

The second sentence uses the phrasal verb look forward. While this idiomatic verb means anticipate, it behaves grammatically and requires a preposition to indicate the indirect object — what you are looking at, or in this case, looking forward to (it's "to" because it's concerned with time).

Thus look forward requires to as a preposition and a noun or noun phrase. See is a verb and therefore not right; seeing is a gerund behaving as a noun and is therefore the right form to use.

I look forward to seeing you.

The first sentence has a wrinkle or two. Want is not a simple verb!

Where a verb is followed by a second verb, that second verb is always in an infinitive form. Because want is not a modal verb (such as do or can) that infinitive form uses to.

I can have it [can is never followed by a to infinitive]
I want to have it [want is followed by a to infinitive]

Want can also be followed by a noun, or noun phrase, or a gerund which acts as a noun; that is, it can be an ordinary transitive verb.

I want an apple
That last cake wants eating

In this case, seeing you is not a noun phrase or gerund, it's a present participle and thus ungrammatical. Therefore the next word must be an infinitive form of the verb (see) and because of that it needs to.

I want to see you.

The wrinkle is knowing that seeing presented as a choice here is a present participle and not a gerund like the "look forward" sentence. The clue is that it has its own object, you, which conflicts with the use of want. Want fundamentally indicates a need, a lack, which must be satisfied. As such, it can only have a single object, the one thing which satisfies that need, so you can't use seeing you. Thus you must use see and that must be a to infinitive.

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You've had a very good go. Thank you! You and Barrie and Edwin have provided a host of interesting and persuasive arguments in your answers. I think they're all much more complete and satisfying than mine. As I said, I'll delete my answer because I don't think it adds anything to what the three of you have said. Thank you all! This kind of effort makes reading what the real experts here have to say worthwhile. – user21497 Feb 9 '13 at 13:45
1) "that second verb is always in an infinitive form" - I take it you are using infinitive in the sense of non-finite? Because the second verb may be a gerund: This car wants washing, He intends going. Indeed, some researchers now claim that contructions with the gerund have been gradually displacing constructions with the infinitive for a century and a half, and the process continues. 2) I am puzzled by your characterizing OP's optional seeing as a participle on the grounds that it takes an object; gerunds have been taking objects since Late Middle English, with increasing frequency. – StoneyB Feb 9 '13 at 19:28
and 3) It seems to me that want takes a marked infinitive (except in the case where the verb is transitive and has the subject of want as its object) because that's the idiom, not because of any substantial difference in meaning between the infinitive and the gerund. As Barrie says, you have to learn what arguments each verb licenses. Some license one, some the other, some both. – StoneyB Feb 9 '13 at 19:32

Want is one of a group of verbs that commonly occur with a to-clause rather than a that-clause. English doesn’t allow a sentence like ‘I want that I see you.’ It has to be ‘I want to see you.’

Look forward to is what the ‘Longman Student Grammar of Spoken and Written English’ calls a phrasal-prepositional verb. That is, it consists of a verb followed by an adverbial particle, followed by a preposition. It can be followed by a noun phrase (‘I’m looking forward to the match’) or by the -ing form of a verb (‘I’m looking forward to seeing you’), but not by to + infinitive.

The simplest way of knowing the difference is to learn the constructions which each verb allows.

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I know that giving rather strange rules which demand quite different analyses of similar-looking constructions can seem worrying / bewildering / infuriating. Perhaps if we look at near-paraphrases it will help a little (perhaps not):

2. I look forward to seeing you.

The string look forward is rarely used without the to (it would then be a less opaque idiomatic usage - don't look at what has happened in the past; look forward/s - and then ahead would probably be preferred anyway). (Google searches for "look forward to" and "look forward" -"look forward to" lend reasonable support to this claim.)

Look forward to has the fairly opaque (not too guessable from its component words) idiomatic meaning, eagerly anticipate. I'd say it has a unitary meaning (although in this case, I can only think of a two-word 'synonym', not a single word one - and perhaps 'anticipate quite eagerly' is closer in sense). Some would class the three-word string as a transitive multi-word verb (and possibly reclassify the to as a particle if pressed to parse individual words).

Notice that a noun as well as an -ing group could occupy the object space:

I look forward to seeing you.

I look forward to playing.

I look forward to the concert.

1. I want to see you.

Here, although there are again arguments for considering want to as a unit (He helped wash up / he helped to wash up; I want to go / je désire aller; But I want to!) there are considered to be more persuasive reasons for us to consider the to as more tightly bound to the base form of the following verb (to make a to-infinitive rather than the bare infinitive):

To see you tomorrow is impossible.

What do I want most? To see John.

I intend to see him tomorrow.

?/* Sorry, what did you say you intend?

Sorry, what did you say you intend to do?

*Sorry, who did you say you intend to?

Sorry, who did you say you intend to see?

*I intend to the concert.

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The second one is a "tri-part phrasal verb" and always takes a noun phrase after it. I look forward to + seeing you/the movie/seeing the movie with you. Does that make sense?

Want will often take an infinitive after it. I want to see the movie.

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Just as the verb 'to be' is so important in English that it has two forms in the past form (I.e. was/were) and we build a cornerstone in English called tenses around it (i.e. present and past tenses). So is the word to for prepositions that we build one half of a "tense" called infinitives (the other half is gerunds). You can think of this tense in the same way as the future tense has two options (I.e. I will or I am going to). Infinitives and gerunds are two verbs back to back with a preposition in the middle optional. You need to figure out if the first verb will produce physical activity. If it will then it's an action verb and second verb will get an ing (a gerund). If the first verb wont produce physical activity then the first verb is stative verb and a to goes between the two verbs. Secondly if the to comes after a two word verb (where putting a verb and infinitive together creates a new meaning) like look forward then to can actually be a part of the verb (e.g. 'look forward to' creates an entirely new meaning than look forward e.g anticipation rather than envisioning). Actually what you have here is a three word verb "look forward to" that will produce physical activity. Thus the verb is "look forward to" and the second verb must end with ing since a physical activity will be produced. 'To' can only change the meaning if it follows another infinitive like 'forward.' When used between two verbs 'to' doesn't change the meaning of a verb it follows unlike all other prepositions. All other prepositions change the meaning of the first verb by becoming a part of the verb (a two word verb). To only becomes part of the verb (and thus changing meaning) if to comes after a preposition that is already a part of a two word verb. Note some verbs may or may not produce physical activity and thus can be used with either to (infinitive) or the ing (gerund) structures. One example is the verb to like. Most verbs are either action or stative but some verbs can be either one because it may or may not produce physical activity. Thanks. God bless. Aaron

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Forward is not an infinitive in look forward to. And infinitives plus gerunds do not a tense make. Rather, they are two of the non-finite forms of a verb in English, the others being the two sorts of participle. – tchrist Nov 2 '14 at 7:12
VERY confusing, and wall of texts are hard to read online. – Mari-Lou A Nov 2 '14 at 16:39

protected by Rathony May 15 at 17:20

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