Grammar guru: must, have to, need to?

Last week’s question was What sounds better to you?

  • This has to be done by Friday (88%, 7 Votes)
  • This has to be done until Friday (12%, 1 Votes)

If it is done until Friday, somebody is doing it day and night until Friday rolls around.
By Friday
just means it’ll be ready on Friday.

This week we ask: What’s the best alternative to saying “You don’t really need to register for the event”?

  • You mustn’t register for the event.
  • You don’t necessarily have to register for the event.

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Teaching English for business communication skills, writing online for learners, translating, sailing whenever I can, from Washington, D.C.

5 thoughts on “Grammar guru: must, have to, need to?”

  1. Can I say…

    “The truck is more bigger than the car”?

    I think: “the truck is bigger than the car” is normal but I have heard a lot of people saying “the truck is more bigger than or……the plane is more longer than…” Is this possible?

    What has more priority for obligation/urgency: ‘I must….I have to….or I need to’?

  2. Dear Christina,
    Those are two interesting questions.

    You’re absolutely right, it’s “bigger than”. But the confusion you hear comes because there are two kinds of adjectives:

    1. big, bigger, biggest; or funny, funnier, funniest (1 or 2 syllables)
    2. perfect, more perfect, most perfect; or beautiful, more beautiful, most beautiful (2 or more syllables)

    Using “more” and “-er” together is not grammatically correct. But you even hear some native speakers saying it. It’s known as an “analytical error”: The speaker has understood a rule and is combining it with a second rule and trying it out on a new word. Quite creative, actually! Kids do it all the time when they are learning their own language (See: Or a learner of English is transferring a grammar structure from his native language (a word that translates as “more”) to an English word he’s heard (like “better”). These errors then catch on in a subculture, like “more better” in Spanglish.

    Here’s a nice grammar link that recaps the basic rules:

    As for your second question about obligation/urgency, this is a cultural and psychological question:

    – “I have to” is straightforward, I have no choice.

    – “I must” repeats what I know what I have to do, what an inner voice is telling me. So I am sending a message to myself, and you are listening to my inner monologue.

    – “I need to” expresses my sense of urgency. If you understand my needs, I can involve you, or put you under pressure by saying “I need to”. If you feel socially responsible, this gives you the social obligation to help me do what I have to do. Very complicated, right? We use it all the time in the States.

    How would you use these three words in your everyday life?

    Have a nice day!

  3. Since you know that I am the English teacher from before, and I have been following your posts, I found your last question interesting and I wished to respond. In daily life, I would say “I have to go now,” or “I have to, I have no choice…” to express an ultimatum or an inevitable kind of urgency (responding also to Christina’s original question). “I must do this in order to succeed,” or “I must accomplish this task,” is, in fact, very appropriately an inner impulsion, as you said, Anne. I agree with you that in expressing “I must + verb expression,” this last expression indicates a truly pressing inner desire to accomplish a task. As in French or Italian or Spanish, the difference between “Je dois” (or “Io devo”) and “Il faut que je + subjunctive tense” (or “E’ necessario che io + subjunctive, etc.), is semantic. Notice that “I must” is normally an expression in the impersonal “Il faut que.” In the last case, I would use “I need to” in these cases: “I need to my best friend; he is sick and in the hospital,” or “I need to save my money,” or “I need check my email, may I borrow the computer after you?”, etc. In American English, “I need to” has replaced using “I must” or “I have to,” perhaps because it sounds more immediate and pressing, or because, as controversial as this is, American culture is more need-oriented. “I need to ask you for help,” instead of “I must ask for your help,” or “I have to ask you to help me.” All are grammatically correct and in use, but only the former is preferred. Also, returning to your point on the sociology of language (linguistic anthropology, in fact), I find that Americans favor an expression that intimates a command of some sort over one that reveals their weakness. If the receiving person feels socially responsible, he or she may certainly be persuaded to oblige when hearing “I need you to…” Though, in your poll on which is better, “You don’t really need to register for the event,” I think I was the one who voted for the latter option. I said it might sound better to say “You mustn’t register for the event,” thinking that mustn’t cleans up the language and tidies up the sentence. Of course, from your question to your first answer option, you transferred the usage of “need to” to “have to,” with the conditional modifier “necessarily.” It is more stylistically correct, I believe, to maintain the tense of the first verb (conditional), but I may have offered for the second option: “You needn’t register for the event” as perhaps a better alternative. I do agree, on second thought, that the first option better expresses the original intent of the prompt! :)

    I have to go now, but I must tell you that this is truly a needed exercise of language and one that many need to consider! 😉 Thank you for explaining to us these intriguing nuances of our English language. -Matteo

  4. Thank you very much, Matteo, for your very interesting comment. Looking at the discussion I think I’ll have to open up some sort of space for Grammar guru discussions. Not sure how yet, outside of these discussion threads.

    mustn’t forbids doing something, e.g.
    “You mustn’t forget to buy some oranges.”

    don’t have to
    + needn’t allow you NOT to do something.
    “You needn’t bring more than 2 kg.”
    “They don’t have to be organic, but it would be nice.”

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