PRESENT TENSES I
Present Simple
1: We use the present simple when something is generally or always true.
2: Similarly, we need to use this tense for a situation that we think is more or less permanent. (See the present continuous for temporary situations.)
3: The next use is for habits or things that we do regularly. We often use adverbs of frequency (such as 'often', 'always' and 'sometimes') in this case, as well as expressions like 'every Sunday' or 'twice a month'. (See the present continuous for new, temporary or annoying habits).
4: We can also use the present simple for short actions that are happening now. The actions are so short that they are finished almost as soon as you've said the sentence. This is often used with sports commentary.
Future Uses
5: We use the present simple to talk about the future when we are discussing a timetable or a fixed plan. Usually, the timetable is fixed by an organisation, not by us.
6: We also use the present simple to talk about the future after words like ' 'when', 'until', 'after', 'before' and 'as soon as'. These are sometimes called subordinate clauses of time.
Present Continuous
1: First, we use the present continuous for things that are happening at the moment of speaking. These things usually last for quite a short time and they are not finished when we are talking about them.
2: We can also use this tense for other kinds of temporary situations, even if the action isn't happening at this moment.
Compare this with the present simple, which is used for permanent situations that we feel will continue for a long time.
3: We can use the present continuous for temporary or new habits (for normal habits that continue for a long time, we use the present simple). We often use this with expressions like 'these days' or 'at the moment'.
4: Another present continuous use is for habits that are not regular, but that happen very often. In this case we usually use an adverb like 'always', 'forever' or 'constantly'. Often, we use the present continuous in this way to talk about an annoying habit.
Future Uses
5: The next use is for definite future arrangements (with a future time word). In this case we have already made a plan and we are pretty sure that the event will happen in the future.
We can't use this tense (or any other continuous tense) with stative verbs.