Modal verbs have some common characteristics:
1.Modal verbs are usually followed by verb forms to form predicates.
2.Modal verbs do not have the same form of the sum of numbers, i.e. the form of the modal verb remains the same regardless of whether the subject is in the first person, the second person, or the third person, and whether it is singular or plural.
3.There are some modal verbs that have a form in the past tense, but this past tense usually does not indicate a tense but rather a euphemistic or uncertain tone.
The specific usage and meaning of modal verbs are as follows:
1."can" indicates capability or objective possibility, and can also indicate request and permission. For example, "I can speak English", "Can you help me with this task?".(Can you help me with this task?) ）”
2."Could" is used to indicate a past ability or possibility, and can also be used to euphemistically request or offer. For example, "he could h**e finished the work on time, but he was ill", could you please give me a hand?(Can you help me?) ）”
3."May" means may, allowed, or desired and is often used to indicate a polite request or inquiry. For example, "She may go to the movies with her friends this weekend", May I borrow your pen?(Can I borrow your pen?) ）”
might" denotes past possible or speculation, and can also be used to denote a euphemistic request or offer. For example, "He might go to the party, but i."'m not sure (He might go to the party, but I'm not sure.)