A modal verb is a type of auxiliary verb used to express ideas such as ability, possibility, permission, and obligation. The modal auxiliary verbs are can, could, may, might, must, ought to, shall, should, will, and would. For example:

• Konah can eat a lot of pies.
  (Here, the modal verb “can” helps to express the idea of ability.)
• Konah might eat that pie before he gets home.
  (“Might” helps to express the idea of possibility.)
• Konah may eat as many pies as he likes.
  (“May” helps to express the idea of permission.)
• Konah should give you some of that pie given you bought it.
  (“Should” helps to express the idea of obligation.)

There are two kinds of verbs:

• Helping verb
• Main verb