Time machine (teenagers): Perfect Tenses

Flash School
Lesson 1: Present Perfect: affirmative sentences
Lesson 2: Present Perfect: ever, never
Lesson 3: Present Perfect: already, just, yet
Lesson 4: Present Perfect: How long + for, since
Lesson 5: Present Perfect vs Past Simple
Lesson 6: Past Perfect: affirmative sentences
Lesson 7: Past Perfect: negative and interrogative sentences
Lesson 8: Past Perfect + Past Simple