One of the hardest things to learn in English is modals, their meanings and when to use them. Modals are sometimes called modal verbs, or helping verbs. In my opinion, it's better not to refer to them as verbs, because they are really not verbs. Verbs express actions (like
eat, talk, go), phenomena (like
rain, believe, live), and states (like
be, have, sit). Modals are those words that we put before verbs to express our attitudes, beliefs, and feelings about the verbs, such as degrees of certainty, politeness, expectation, necessity and advisability. Most modals are one word (like
must, might, can, should, and
would), but there are also phrasal modals that consist of more than one word (like
have to, have got to, be able to, ought to, and would rather). One tricky thing about modals is that one modal can have several different meanings and uses, such as
would. For example,
would like is a polite way to say
want,
would rather expresses a preference,
would can be used for a polite request, such as
Would you mind helping me?, and
talking about something that you did repeatedly in the past, such as
I would ride my bike every day when I was a kid.
Many ESL students think that the only modal we use to express necessity is
must. Actually, we don't use
must very much at all when we speak, and only when we are referring to rules that you
must follow or in legal written documents, such as
You must pay your rent on the first day of each month (in your rental agreement)
. Otherwise, when we refer to necessities, we use
have to, or in more informal speech,
have got to.
Some ESL students are surprised to learn that we give advice with both
should and
ought to. It probably doesn't help that in normal, fast speech we say
otta instead of
ought to, just like we say
wanna instead of
want to. So
should and
ought to (otta) mean the same thing and they are equally common. Learning how to use modals is more like learning words than learning grammar. You learn how to use them best by listening to how native speakers use them and in what situations.