How do we use the present perfect with future clauses of time?

Today, let's talk about how we the present perfect with future clauses of time.
 

We've already talked about how we often use the present simple after time words like 'when', 'as soon as', 'after' and 'once'.
 

• I'll call you when I get home (NOT: when I will get home).

We can also use the present perfect after the time word, to emphasise that the action with the present perfect will happen before the other action. Both actions are still in the future.
 

• I'll call you after we have had lunch (this emphasises that lunch will happen first).
• We'll meet as soon as you've finished work (finishing work happens first, then meeting).

What's the difference?
 

• I'll call you when I finish work.
• I'll call you when I've finished work.
   

These sentences are very close in meaning. The second one emphasises that the finishing will happen before the calling, not at the same time.

Let's review!
 

Make sentences using the present perfect.
 

1. She'll meet us when she ______________________________ (be) to the gym.
2. I'm going to clean the house after the children ______________________________ (leave).
3. We'll set off as soon as John ______________________________ (call).