More indepth coverage

I need to know what these tenses of the present are called and when one uses them.

I am running. ( my guess is that this one is used as a perfect present tense )

I run. ( this is something more in general as in something that the person does do, or is not doing at the time but usually does )

I do run. ( I have no clue ) ( I’ve never heard this used )

Have a look at the two pieces I’ve written under the heading esl lessons - Present Tense and Progressive Forms.

Sometimes the auxiliar “do” is used to emphasize certain actions, for example: I don’t run in the afternoons but I do run in the mornings.

Do you have one on the past tenses, also Alan?

Unfortunately not but it has certainly given me an idea!