2014-07-29 Structure: modals for obligation (4)

Greg Malivuk
[email protected]
http://www.pastebin.com/u/gmalivuk
---
faux pas - a social mistake, where you do something rude or impolite because you don't know the correct way to act
---
www.waitbutwhy.com/2014/04/everything-dont-know-tipping.html
(How much of a tip different workers expect in New York City)
---
Modal Verbs: (any subject) + [modal] + base form
can	could
shall	should
will	would
may	might
must
ought to
had better
(You cannot use more than one modal together.)

"similar expressions" or "phrasal modals" or similar:
have to - similar to "must"
be supposed to - similar to "should" and "ought to"
be going to - similar to "will"
be able to - similar to "can" and "could"
(these can change with subject and tense, and can be combined with modals)
---
Obligation and Necessity:
(necessary = no choice:)
You must go to school on time.
You have to do your homework.
I am to do my homework before I can go outside.
I had to go to the doctor yesterday.
You must not be late to class.
You can't park here after 6pm.
We aren't allowed to have candy before dinner.

(advisable = you have choice, but some choices are better:)
You had better study tonight. (If you don't, you'll fail.)
You should study every day. (This is the best choice.)
You ought to study every day. (= should)
You should have studied.
(It was the best choice, but you didn't do it.)
You shouldn't have stayed out so late.
(It was a bad choice, but you did it.)

(weak suggestion = this is one option among many:)
You could take the bus to New York.
You might want to get a reservation first.
You could have taken the bus.
(It was one of your options, but you didn't do it.)

(no obligation = you can do this or not, it doesn't matter:)
You don't have to make a reservation.
You can buy tickets online.
You didn't have to bring a gift.
---
(expectation = experts or authorities expect this:)
It's supposed to rain later today. (experts expect it)
I'm supposed to be home by midnight. (my parents expect it)
Class was supposed to start at 9. (but it didn't)
---
Homework: exercises 1 and 2 (p. 56-59)