1) Present Simple is used to talk about: — Habits (my father drives to work) — How often things happen (It never snows in the Sahara desert) — Permanent situations (I live in London) — General truths and facts (Water boils at 100 C) — General abilities (I play the piano) — States — thinking, emotions, the human senses, appearance, relationships between things (I know him and his brother; I see much better with my new glasses) — The future in timetables (My train leaves in an hour) — The future in time clauses (I'll tell Carrie when I see her) 2) Present Continuous is used to talk about: — Actions in progress at the moment of speaking (come inside — it's raining) — Temporary series of actions (I am learning to drive) — Temporary situations (We are staying at the Grand Hotel) — Changing situations (This city is getting bigger every year) — Annoying habits (usually with always) (You are always losing your keys!) — Definite arrangements and plans for the future (We are having a test tomorrow) 3) Modal verbs are auxiliary verbs which express things like possibility, obligation, etc.Modal verbs: — Don't change for person or tense (He might go to the cinema (not he mights) — Don't use do in questions (Can you play the guitar? (not do you can play) — Are followed by the bare infinitive (without to) (I think he will call… (not he will to call) — Don't have an infinitive (I hope to be able to attend the meeting (not I hope to can attend…) Modal verbs include will, would, can, could, may,should, must, might, shall and ought to. Допишу в следующем ответе.
