Grammar Point Presentation: Must/Have-TO

beginr

eslabout

hafta

modals in teaching

difficulties teaching modals

musta

INTRODUCE

Robin Scarcella | http://www.irc.uci.edu/trg/139.html (u_cal irvine) modals must/have-to (& 3rd person '-s' are late aquisitions (advanced students)
English Grammar for ESL Teachers (sequence) http://www.csus.edu/indiv/m/marshallf/cours110Q/110q_schedule_fall98.htm (cal state sacramento)
This class introduced modals in week 8 of 15

Common Errors

Must/Have To troubleshooting: http://www.collegeem.qc.ca/cemdept/anglais/musthmts.htm
lists as common errors:

combining forms - 'must to' or 'have+verb base'
using 'must not' in place of 'do not have to' or vice versa
expressing past w/ 'must+verb base'
expressing future w/ 'will+must+base'

from: http://www.uark.edu/campus-resources/qwrtcntr/resources/handouts/eslteacher.html:
Misuse of modal auxiliaries--Out of the twenty-three English helping verbs, nine, called modals, can only work as helping verbs. These are can, could, may, might, must, shall, should, will, and would; verbs that can be either helping or main verbs are forms of do, have, and be. Some students may have trouble coordinating helping and main verbs, but it can help to tell students that modal auxiliaries do not agree in number with the subject (He cans do it) and that modals are followed by base, not finite verb forms (He can does it)

FORM

have to is conjugated like regular verb, thus requires auxiliary in negation or question form.
(http://www.spjc.edu/tsc/esl/modalsandverbs.htm)
informally spoken as hafta, 'got to', gotta - often source of confusion for Ss

MEANING

from the American Heritage Dictionary at reference.yahoo.com/

must
AUXILIARY VERB 1. To be obliged or required by morality, law, or custom: Citizens must register in order to vote.
2. To be compelled, as by a physical necessity or requirement: Plants must have oxygen in order to live.
3. Used to express a command or admonition: You must not go there alone. You simply must be careful.
4. To be determined to; have as a fixed resolve: If you must leave, do it quietly.
5 a. Used to indicate inevitability or certainty: We all must die.
b. Used to indicate logical probability or presumptive certainty: If the lights were on, they must have been at home. INTRANSITIVE VERB: Archaic To be required or obliged to go: “I must from hence” (Shakespeare).
NOUN: Something that is absolutely required or indispensable:
* Promptness on the job is a must.
* Comfortable boots are a must when going on a hike. ETYMOLOGY: Middle English moste, from Old English mste, past tense of mtan, to be allowed. See med- in Appendix I.

Contrast the above with
'have' - (14 of 15): To be obliged to; must: We simply have to get there on time.

USE

The British Council http://www.learnenglish.org.uk/grammar/archive/mustvshaveto.html
MUST	HAVE TO
obligation or neccessity NO PAST - pres/fut only	obligation or neccessity present, future, or past
certainty present or past	certainty NO PAST - pres only
negative form must not = forbidden	negative form don't have to = optional
speaker as source of authority	external source
CONTRAST THESE (saved from bartleby.com in local html share)
must	have to
The below info was excerpted from http://www.easyenglish.com/lesson.asp?01infer.txt
LESSON	MOOD (function)
01infer	inference/conclusion
02oblig	obligation
03advice -	recommendation/advice (informal form - requires interpersonal intimacy, else rude)
04suggst	suggestion
05expect	expectation
06probab	probability
07permit	permission/concession (if you must/if you have to)
08reques	request (indirect please stop - must you ..? - do you have to ..? \| - indirect request about obligation)
09offer	offer (not this one not directly anyway)
10possib	possibility (no - not directly anyway - see probability)
11abilit	ability/capacity (no not directly anyway)
12predic	prediction (see probability)

leftovers

grammar point web sites
Very interactive Must/Have To activity from ESL Blues: http://www.collegeem.qc.ca/cemdept/anglais/havetmus.htm#top
No good info though - but there are some minimal 'rules' at http://www.collegeem.qc.ca/cemdept/anglais/musthavt.htm#rules
specifically,
**
" In the affirmative have to / must both express the idea of obligation. (It is necessary that you do something.) However, must is only used in the present, and is never used after 'will' or 'may.' I must / have to get up early because I start work at 8 a.m. I will must / have to leave work early if the snowstorm continues. In the negative only the verb have to (do/does not have to) expresses the idea of obligation: (It is not necessary that you do something.) You don't have to pay for children. They can come in for free. In the negative must (must not / mustn't) is similar to an imperative: Do not do something: You mustn't smoke in the corridors. (= Don't smoke in the corridors.)"
**

***5/3 English Grammar for ESL Teachers (sequence) http://www.csus.edu/indiv/m/marshallf/cours110Q/110q_schedule_fall98.htm
Introduced modals in week 8 of 15

Teaching Resources Guide - Article - search page for 'modal' http://www.irc.uci.edu/trg/139.html

Helping and Modal Auxiliary Verbs - overview