Your track

I am doing — actions happening now

I do — habits, repeated actions, general facts

now / temporary vs usual / permanent

know, want, believe, understand…

I did — completed past events

I was doing — in progress at a past moment

I have done — past linked to now

recent events, unfinished periods

I have been doing — continuing until now

I've been doing vs I've done

Asking about duration

duration vs starting point

connection to now vs finished past

finished / unfinished time periods

I had done — before another past event

I had been doing — duration up to a past moment

Possession and other uses of have