I have eaten/ I had eaten
Present Perfect Simple
Subject+ have/has + 3rd column Tips:
I have eaten meat and chips for- since- just- already- never
Present Perfect Continuous
Subject + have/has+ been+ V-ing
I have been eating with my friends for two hours.
Mixed exercises
Past Perfect Simple Past Perfect Continuous
Subject + had+ 3rd column Subject + had been + V-ing
Positive: I had eaten pasta before you came. I had been eating pasta before the match.
Negative: I hadn’t eaten I hadn’t been eating pasta
Interrogative: Had you eaten pasta? Had you been eating pasta before?