What Are Modal Verbs of Probability?

by | Nov 2, 2017 | GrammarSpot | 0 comments

What Are Modal Verbs of Probability?

by | Nov 2, 2017 | GrammarSpot | 0 comments

Modal verbs of probability may seem like intimidating parts of language, but they’re actually verb structures that are found in everyday speech and writing. When you’re looking through the latest gossip magazine regarding George and Amal Clooney’s latest news and find yourself gasping, “That can’t be true!” you are using a modal verb of probability. Modal verbs are essentially helping verbs that add information to the sentence.

List of Modal Verbs of Probability

When talking about the present, modal verbs of probability express a guess or suggestion. Here are some common present modal verbs.

Modal Verb of Probability Meaning
Can’t + infinitive I’m sure this isn’t so.
Can This is a general possibility.
Could Maybe.
May Maybe.
Might Maybe.
Must I’m pretty sure this is true.
Will I’m very sure this is true.
Won’t I’ve very sure this isn’t true.
Should This is probably true.

Present modal verbs of probably are often constructed with “be” following them.

  • George must be on the plane by now.
  • Katie may be late to the movie.
  • Flying can be too expensive.
  • Drew can’t be going to the party.

Past Modal Verbs of Probability

You can construct past modal verbs by adding “have” and a past participle to the modal verb.

  • George must have gotten on the plane.
  • Katie might have been late to the movie.
  • Flying could have been too expensive.
  • Drew can’t have gone to the party.

It is important not to confuse modal verbs like “should” and “could” with their other modal verb roles. When used as a modal verb of probability, “should” means that you assume something happened if everything is as you expect it to be.

  • PRESENT: The bus should be leaving.
  • PAST: The bus should have left.

When paired with an infinitive, “could” expresses a general possibility in the past and is used as the past tense of “can.” In the present tense, “can” talks about general possibilities that we understand to sometimes be true. “Could” is the past tense version of this type of “can.”

  • PRESENT: Gas prices can be high in the summer.
  • PAST: Gas prices could be high in the 1970s.

Note the present tense of “be” even when referring to the past with both “should” and “could.” This is not to be confused with pairing these verbs with “have” and a past participle, which talks about specific past possibilities or obligations.

Past Modal Verbs of Certainty

When you are certain that something has occurred, then you can use “will” or “won’t” with “have” and a past participle.

  • Phil will have arrived by now.
  • Cara won’t have left the office until well after closing hours.

Making Sense of It All

When using modal verbs of probability, things can quickly get confusing, but ensuring proper grammar could end in your favor. When expressing probability in present tense, pair a modal verb up with an infinitive. When expressing probability in the past tense, add “have” and a past participle to the modal verb.

What is the most impressive use of modal verbs of probability you have ever come across? Do you have any additional tips to offer on their use? Share them in the comments below!

Britainy Sorenson

Britainy Sorenson has been freelance writing since 2011 in between time spent with her best friend and husband and caring for three active and amazing little boys. She earned a BA in Japanese, an MA in Second Language Acquisition & Teaching, and a Graduate Certificate in TESOL from BYU. When her fingers aren't flying at the keys, she enjoys reading, video games, drawing and learning new crafts.
Did you know we write awesome content?

Did you know we write awesome content?

Let us save you time and money by creating the content you need! Give us your email to learn more.

Thanks! We'll send you information shortly.

Pin It on Pinterest

Share This

Share This

Share this post with your friends!