Shall and will are two of the English modal verbs.

The same modal verbs are also often used with present rather than future reference.

An example of such a word is the modal verb can.

Finally, English mood is now usually shown by using modal verbs.

For more details and other similar cases, see the relevant sections of English modal verbs.

The condition can also be expressed using the modal verb should.

The modal verb could is also sometimes used as a conditional (of can).

There are other modal verbs also found in this space.

They are sometimes, but not always, categorized as modal verbs.

It takes the place of English modal verbs such as can, could, would, might, may.