english grammar
we are closed
or we closed
why

Question

english grammar
we are closed 
or we closed 
why

Answer

We are closed. This is a complete sentence in present tense for a store which has closed for the day.
We closed... usually precedes an explanation... We closed the store for the weekend. It may be said as a response to a question.  
Why aren't you working this weekend? 
We closed... this is short for: We closed for the weekend.

Answer

It depends on whether you are talking about the situation NOW or an event in the PAST.  Examples:

NOW: You can’t come in now.  We are closed. 
PAST: You can’t come in now.  We closed 20 minutes ago.