Present perfect in future time clauses

The idea

After when or once, use have or has plus a past participle to emphasize completion before a future action. The main clause can use will or another suitable form. The present simple is often possible too, with less emphasis on completion.

Examples

• Once I have finished the report, I will call you.
• When she has packed her bag, she will meet us downstairs.
• Once the rain has stopped, the children can play outside.
• We will plant the seeds when the soil has warmed up.
• Once they have checked the tickets, they will open the doors.
• You can borrow my bike when I have repaired the brakes.

Watch out

Do not normally put will in the time clause: say when she has finished, not when she will have finished.

Try it yourself

1. Choose the correct option. Once we ___ dinner, we will wash the dishes. (have eaten / will have eaten)

   Show answer or example answer

   have eaten

   have eaten places the meal before washing the dishes.

2. Choose the correct option. When he ___ the form, he can send it. (has completed / will have completed)

   Show answer or example answer

   has completed

   has completed agrees with he and places completion before sending.

3. Choose the correct option. I will unlock the gate once you ___ the dog inside. (have brought / will have brought)

   Show answer or example answer

   have brought

   have brought places bringing the dog inside before unlocking the gate.

Use it today

Write a sentence about what you will do once you have completed a task.