Modal verbs do not show an action that can be performed. They just tell us about the attitude of a speaker. They indicate the mood of a speaker. For example, in the sentence,
He can work 14 hours a day
the main verb is work and it’s the only verb in the sentence as it shows an action. The modal verb can doesn’t indicate an action. However, it tells us how the speaker feels that someone is capable of working for 14 hours a day. The assumption or belief of the speaker about someone’s ability to do something shows his attitude or mentality in the sentence. The speaker thinks someone is capable of doing something. Such attitude is demonstrated in the above sentence by the modal verb can. Like can showed someone’s ability to do something, different modal verbs show different moods or attitudes of a speaker.
Following is the list of Modal verbs:
Let’s study them in a little more detail.