Part 2: Verbs
Semi-Modal Verbs
Examples
Before the mid-19th century, most people weren’t able to read.
I am supposed to mark you absent if you are 10 minutes late.
You have to be more careful.
We’re going to write a letter to the editor.
Definition
Phrasal modals carry similar meanings to their corresponding “pure” modal verbs (can, could, may, will, should, must, etc.) but with some differences in function and use. Like all modal verbs, they add interpersonal meaning to a clause: this means, they express stance, opinion, or subjectivity. However, sometimes, the authority or obligation is more external with a phrasal modal verb, whereas it may be internal with a pure modal. For example, if you say that you must leave a party [pure modal], the listener will probably assume that you have a reason why you want to leave. However, if you have to leave [semi-modal], there is something compelling you (it’s a school night, your parents want you home by 11, your carriage will turn into a pumpkin, etc.).
The phrasal modals can be lined up with their related pure modals:
|
Modal |
Phrasal modal |
|
can, could |
be able to |
|
will |
be going to |
|
must |
have (got) to |
|
should, ought to |
be supposed to |
|
may, might |
be allowed/permitted to |
Discovery
Form
The big structural difference between pure and phrasal modals is that phrasal modals start with a verb that needs to be inflected (be or have). This means they can take different tenses (I am able to, I was able to, I will be able to …). Also, all the phrasal modals end with to, so they appear to be followed by the to infinitive (I have to go), not the bare infinitive (I will go).
Careful!
Some learners will try to add to after a pure modal by analogy with phrasal modals (*I must to go).
It is easy for MLLs to forget the be or have verb (*I going to, *she supposed to). This does not usually cause a comprehension problem in speaking, but it is considered an error in most written registers.
Phrasal modals can be heavily reduced in fluent speech. For example, “We have got to go” naturally sounds like “we gotta go”; “I’m going to look” becomes “I’m gonna look” (or in some varieties, “I’mma look”). These reductions are neither slang nor incorrect, and some of them occur even in quite formal speaking situations like lectures or political speeches (gonna, wanna, oughta). However, they should be avoided in writing unless the writer is trying to reflect the patterns of spoken English, for instance in dialogue.
Learners should be aware that the negative forms of must and have to behave strangely:
You must/have to register online. (both forms mean it’s a requirement).
You must not register online. (It’s not allowed)
You do not have to register online. (It’s not required)
Functions
Many grammar textbooks go to great lengths to differentiate phrasal and pure modals in terms of their meaning and use. As you may have seen if you disagreed with the answers to the Discovery task, the reality is much messier and may be difficult to detect. However, here are some consistent differences in function and meaning which are useful to teach:
Be able to is used for past time, which isn’t always possible with could:
I was able to buy the tickets yesterday (and I did)
?I could buy the tickets yesterday (were you able to, or was it possible to? – this is unclear)
Will and be going to have somewhat different functions, although it’s hard to imagine a context where a speaker would be misunderstood for choosing the wrong form. Typically, grammar books teach this distinction:
will: sudden decisions, promises, schedules (e.g., I have a good idea! I’ll turn off my phone at night. / I’ll pay you back tomorrow. / We’ll take the final test in the last class.)
be going to: future plans, actions that can be predicted from the present, weather (e.g. it’s going to rain tomorrow; I’m going to spend the holidays with my family)
Should, must, can, and may are pure modals, so they suggest that the speaker is expressing an internal motivation. Supposed to, allowed to, and have to suggest that the authority is external. This distinction is quite subtle and not always clear, but compare:
I should exercise more (I know I need to do this)
I’m supposed to exercise more (my doctor tells me, but I’m not convinced)
I must make an appointment (because I want to).
I have to make an appointment (or there will trouble).
You can/may turn your paper in late (because I’m giving you permission).
You’re allowed to turn your paper in late (because that’s the syllabus policy).
Exercises
Additional practice:
- What are some rules in your school or classroom? For example: you may drink during class, but you are not allowed to eat. Make a list and think about your choice of pure vs. semi-modal verbs. Do they suggest whether the rule was imposed by you or by another outside authority? Are some of the rules stricter than others?
- Here’s a simple practice exercise from American English, the State Department’s English website.
- Another quick online practice exercise from OUP, with both pure and semi-modal verbs.
- This open textbook chapter has some good advice and practice exercises. For example (source: Building Academic Writing Skills Copyright © 2022 by Cui, Lin)
Use modals of possibility to write three guesses why seafood is popular on Valentine’s Day in the U.S.
Use modals of expectation to write three things you are supposed to know when you go to an American family for dinner.
Use modals of preference to write three choices of food on New Year’s Eve in your home country.
