Comunismo , Inicios

Present Simple (I do, he does...)
A Fact, habit or a regular action:
Demi is a songwriter. She writes songs (Fact)
Demi always writes in themorning (Habit)
Demi writes two songs a month (Regular action)

Present Continuous (I am doing, she's doing, we're doing...)
A temporary action inprogress in the present:
Demi is currently writing a song

Present Perfect Continuous (I've been doing, she has been doing...)
An action that hasalready started and is still going on:
Demi has been writing songs since she was 14
Present Perfect (I've done, she has done...)
a) With an actionverb. A completed action without a specified time in the past
Demi has already written 40 songs
b) With an state verb. "to be" , "to have", "toknow". Replaces Present Perfect Continuous
Demi has been (been being) a songwriter for 5 years
I have known (I have been knowing) demi since 2010Past simple (I did, she did...)
A completed action at a specified time in the past
Demi wrote "Shut Up And Love me" 3 years ago
Past continuous (Iwas doing, we were doing)
Action in progress in the past either:
a) when a shorter action took place
b) at a very precise moment
Demi was writingfix a heart when she became ill
Past Perfect (I was doing, we were doing)
Action that was completed in the past either:
a) before another actiontook place
b) before a very precise moment
Demi had written skyscraper before she became ill
Past Perfect Continuous (I was doing, we were doing)