ever / never
Have you ever been to London?
My brother has never worked abroad.
2- Unfinished actions
for / since / how long...?
How long have you worked here in La Pineda?
I've worked here for 6 years.
I've worked here since 2007.
3- yet / already
Have you finished your homework yet?
No, not yet. I haven't finished it yet.
Do you want to see this film?
No, I've already seen it.
4- Recent actions
My sister has just started a new job.