Bon's tips EFL exercise

PAST SIMPLE - PRESENT PERFECT SIMPLE in contrast

Ejercicio para 4º ESO.
(An exercise for Intermediate students.)

Rellena los huecos y comprueba tus respuestas.
(Fill in all the gaps, then check your answers.)

1. Just a moment! I (think) of a good idea yet!
2. They (believe) that for ages!
3. How long (you/work) there before coming here?
4. I have watched that movie four times since it (come) out.
5. Someone (eat) my sweets. There aren't any left.
6. I look tired because I (visit) customers all day.
7. I (not wear) any other t-shirt since I bought this.
8. She (work) on the report for more than 2 hours and she still hasn't finished.
9. I haven't seen them since they (buy) their new car.
10. I visited my friend in Barcelona last summer, but I (not write) to him since.