Take the 2-minute tour ×
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.

I read a message from an American friend saying "If I must leave [place], [...]". What´s the difference between "If I must" and "If I had to"? Is there a subtle difference in meaning?

share|improve this question
The first implies that it has already been asked of oneself, while the second does not. That is my take on it, but others might see it differently. –  American Luke Aug 6 '12 at 21:35
This question is asking to compare a present tense form with a subjunctive form; if the intent is to ask the difference between "must" and "have to", and not between present tense and subjunctive mood, the question should be reworded so responders can properly address what is intended to be asked. –  Pantalones Aug 7 '12 at 2:03

3 Answers 3

The difference is seen in the following clause in each sentence. Take these examples:

If I must leave my employer, I shall bring the company down.
If I had to leave my employer, I would bring the company down.

The first is looking a distinct possibility, even probable; while the second is merely hypothetical and may not happen at all.

share|improve this answer
Is the second sentence using the subjunctive mood, as in "If I were rich, I would live on Long Island"? –  kiamlaluno Aug 6 '12 at 21:49
@kiamlaluno I suppose it is. But the question did not ask about "If I must"/"If I have to" (where the second is less hypothetical but not as probable as the first). –  Andrew Leach Aug 6 '12 at 21:59
I know; it was just a way to introduce the OP to the subjunctive mood. ;) –  kiamlaluno Aug 6 '12 at 22:00

Let me answer by example:

If I read "If I must go out in the rain, I will bring my umbrella" I would understand that the person does have to go out into the rain, and is telling me that they're about to go get their umbrella because they're about to go out in the rain.

If I read "If I had to go out in the rain, I would bring my umbrella" I would understand that the person is expressing a preference about a hypothetical situation. They don't have to go out in the rain at this time, but if they did, then they would want to get their umbrella.

In the first one, the going out in the rain has already been decided. In the second, the going out in the rain is not an immediate concern, but a situation that the person is prepared for.

share|improve this answer

Have to contrasts with must in that it usually expresses an obligation imposed by someone other than the speaker. Had to is the past tense of have to and may be used in cases where a past equivalent of must is required. Need to is used where there is not such a strong obligation, but where completing the action will satisfy a particular requirement.

share|improve this answer
I disagree on two points: 1) The only lexical difference between 'have to' and 'must' is one of register. 2) In this case, 'had to' is not past tense but subjunctive mood. –  StoneyB Aug 6 '12 at 22:16
I feel uncomfortable with the second sentence although I believe it is a grammatically correct use of the subjunctive. This may reflect either that use of the subjunctive is in decline or possibly that my use of English is not strictly correct. @StoneyB –  Elberich Schneider Aug 6 '12 at 22:27
@StoneyB. What do you mean by difference of register? Is one of the verbs more colloquial than the other? And which is the more colloquial one? –  Paola Aug 6 '12 at 23:45
@Paola - In US colloquial usage 'must' is rarely used except to express high probability (That must be Joe making all that noise") or emphatic desire ("There must be something you can do about it"). However, 'have to' is rare in formal usage. –  StoneyB Aug 7 '12 at 0:09
@Xavier - I'm not clear what you're uncomfortable with. That "If I had to leave" is subjunctive is determined not by the form of the verb - the same form is used for past - but by the subordinating conjunction 'if'. Yes, use of the subjunctive is declining. Yes, it's possible that your use of English is not strictly correct - but it's likely to be more correct than that of most US native speakers, who lack the enormous advantage of learning a second (or third, fourth, &c) tongue. –  StoneyB Aug 7 '12 at 0:20

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

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