There are numerous word formation processes: clipping, blending, back formation, acronymy, derivation, compounding.
Modals, on the other hand, are special verbs which express varied modalities: ability, refusal, prohibition, obligation, suggestion, advice, request; permission, certainty, offer, possibility, prediction, wish.
Conditionals are used to speculate about something. There are real and unreal conditionals and in each are different verb forms.
Teacher Jeanille