Adverbial clauses of time

After, Before, When

Key Time Expressions used in Adverb Clauses

The time expressions after, before andwhen are used to indicate when something happens in the past, present or future. Each is a subordinating conjunction which introduces a dependent clause and can be used at the beginning or in the middle of a sentence.

AFTER

The action in the main clause occurs after what occurs in the time clause with after. Notice the use: 

Present: What always happens after something else occurs.

Time clause: present simple
Main clause: present simple

Alison checks her mail after she gets home.
David plays golf after he mows the lawn on Saturdays.

BEFORE

The action in the main clause happens before the action described in the time clause with 'before'. Notice the use:

Present: What happens before something else occurs on a regular basis.

Time clause: present simple
Main clause: present simple

I take a shower before I go to work.
Doug exercises every evening before he eats dinner.

WHEN

The action in the main clause happens when something else occurs. 

Present: What always happens when something else occurs.

Time clause: present simple
Main clause: present simple

We discuss the bookkeeping when she comes every month.
Susan plays golf when he friend Mary is in town.

See the video about adverbial clauses of time

Exercise 1: Time clauses 

Exercise 2: 

Time clauses