After, Before, When

Key Time Expressions used in Adverb Clauses

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The time expressions after, before and when are used to indicate when something happens in the past, present or future. After, before and when introduce a full clause and require a subject and verb. Therefore, the time expressions after, before and when introduce adverb clauses.

Each time expression uses different tenses depending on whether the action occurs in the present, past or future. However, the general rule is that time expressions take the simple form of a given tense.

In in other words, after, before and when are followed by either the present simple for present and future situations, or the past simple for past events. The following guide provides an explanation past, present and future use indicating tenses required for both the time clause and the main clause. Examples are provided for each usage to provide context.

After

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

Future: What will happen after something occurs.

Time clause: present simple
Main clause: future

Examples:

We'll discuss the plans after he gives the presentation.
Jack is going to propose to Jane after they have dinner on Friday!

Present: What always happens after something else occurs.

Time clause: present simple
Main clause: present simple

Examples:

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

Past: What happened after something (had) occurred.

Time clause: past simple or past perfect
Main clause: past simple

Examples:

They ordered 100 units after Tom (had) approved the estimate.
Mary purchased a new car after she (had) researched all her options.

Before

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

Notice the use of tenses:

Future: What will happen before something else occurs in the future.

Time clause: present simple
Main clause: future

Examples:

Before he completes the report, he will check all the facts.
Jennifer will speak with Jack before she makes a decision.

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

Time clause: present simple
Main clause: present simple

Examples:

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

Past: What (had) happened before something else occurred at a point of time in the past.

Time clause: past simple
Main clause: past simple or past perfect

Examples:

She had already eaten before he arrived for the meeting.
They finished the discussion before he changed his mind.

When

The action in the main clause happens when something else occurs. Notice that 'when' can indicate different times depending on the tenses used. However, 'when' generally indicates that something happens after, as soon as, upon something else occurring. In other words, it happens just after something else occurs. Notice the use of tenses:

Future: What happens when something else occurs in the future.

Time clause: present simple
Main clause: future

Examples:

We'll go out to lunch when he comes to visit me. (general time)
Francis will give me a call when he gets the confirmation. (after in a general sense - it could be immediately, or later)

Present: What always happens when something else occurs.

Time clause: present simple
Main clause: present simple

Examples:

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

Past: What happened when something else (had) occurred. The past tense of 'when' can indicate that something happened regularly or one specific time in the past.

Time clause: past simple
Main clause: past simple

Examples:

She took the train to Pisa when he came to visit her in Italy. (once, or on a regular basis)
They had a great time seeing the sights when they went to New York.