Modal verbs Туслах үйл үг Can / Could / Must/ Be able to..
Modal verbs give additional information about the mood of the main verb that follows it. In other words, they help to incorporate or add the level of necessity: (must -obligation, requirement, no choice); (should - recommendation); (can/could-it is possible); and (may/might - option, choice) The Modal verbs always come before the verbs. But the verb should be in Infinitive form. You must not put to before the verb.