Present perfect simple

Formula: S + have/has + past participle

• In an action that began in the past, but we don’t know exactly when.

Ex.:
- I have (already) been to London.
- Have you studied for the test?
- They haven’t finished their Christmas play (yet).

Expressions to use:
-Yet (end of the sentence in negative),
-ever,
-never,
-just,
-already (after the verb have/has),
-since,
-for,
-recently (begin of the sentence)