Modal

A modal verb is an auxiliary that can be used to change the gramatical mood of sentence.
Los verbos auxiliares "modales" son verbos que ayudan a otros verbos para expresar diferentes funciones como: obligacion, habilidad, consejos, opinion, prohibicion, y mas. Los siguentes son verbos auxiliares modales: will, can, could, should, might, must, shall, would, ought, to, etc.

Present Preterite
-shall -should
-will -would
-may -might
-can -could
-mote -must

Caracteristicas:

1.- Su forma no cambia (i can, he can, she can).
2.- Se usa con el infinitivo sin "to".
3.-No se usan con "do" o "does" para formar preguntas (do you like to dance?).
4.-no se usa con "dont" o "doesnt" para formar negativos (I cant dance, he cant dance).

Formas negativas

will= will not- wont
can= can not- cant
could= could not- culdnt
should= should not- shouldent
might=might not
must= must not- mustnt
shall= shall not- shouldnt
would= would not- wouldnt

Oraciones:

-I cant dance
-i can dance
-can you dance?

-we will help
-we wont help
-will we hwlp?