Present Perfect Simple

irregular verbs

have+ participle form

They have spoken

They have not spoken

Have they spoken?

have+infinitive+-ed

They have worked

They have not worked

Have they worked?

I have been waiting for you

I have not been waiting for you

Have I been waiting for you?

Exceptions when adding -ing

After a short, stressed vowel, the final consonant is doubled

sit--->sitting

final "ie" becomes "y"

lie-->lying