Lesson

When I do/When I've done, When and if

Time clauses

≈ 15 min 8 block(s)

Text

When I do / When I've done — Introduction

This lesson explains how to use time clauses with when (When I do / When I've done) and how when differs from if. You will learn which verb forms to use, why we avoid will in subordinate time clauses, and how to express certainty vs possibility.

  • Use the present simple after when for actions that will happen in the future: When I finish, I'll call you.
  • Use the present perfect after when to show an action completed before another future action: When I've done the audit, I'll send the report.
  • Use if to express a condition or possibility; use when when the event is expected to happen.

Remember: no will in the when-clause; use present simple or present perfect depending on whether you stress completion.

Table

When / If — Common structures

Structure Meaning Example
When + present simple → main clause with will A future event that is expected to happen When I finish the report, I will email it to the team.
When + present perfect → main clause with will An action completed before another future action When I've finished the audit, I'll submit my recommendations.
If + present simple → main clause with will A possible condition (not guaranteed) If you approve the budget, we'll start next Monday.
When + present simple (general truth) Repeated events or facts When customers request a refund, we check the order history.
No will in the when/if clause Use present tenses in the subordinate clause, will in the main clause Incorrect: When I will finish → Correct: When I finish

Tip

Key rule: tenses and certainty

Choose the tense based on time and completion:

  • Use present simple in the when-clause for future time: When I finish, I'll call.
  • Use present perfect in the when-clause to emphasize completion before the main action: When I've finished, I'll call.
  • Use if for uncertain conditions: If you can join, tell me.

Never use will in the when-clause; reserve will for the main clause that follows.

Example

Examples in context

When I finish the presentation, I'll upload it to the shared drive.

When I've checked the figures, I will send the updated forecast.

If you approve the proposal, we'll begin the recruitment process.

When customers sign the contract, we issue the invoice.

Tip

Common mistakes to avoid

Watch out for these universal errors learners make with when/if and time clauses:

  • Using will in the when-clause: Incorrect — When I will finish. Correct — When I finish.
  • Confusing when and if: use when for expected/future facts, if for possible conditions.
  • Choosing the wrong tense: use present perfect when you need to show completion before another action.
  • Incorrect word order in questions and clauses: keep the subordinate clause structure intact.

Focus on tense choice and the difference in meaning between when (certainty) and if (possibility).

Quiz

Choose the correct sentence:

Hint: Remember: no will in the when-clause; use present simple there.

Quiz

Complete: _____ I have completed the audit, I'll submit the report.

Hint: Think about which word introduces a time clause for expected events.

Quiz

Choose the sentence that expresses a possible condition (not certain):

Hint: Consider whether the event is definite (when) or conditional/possible (if).

Key Points

GrammarPoint

when

conjunction CEFR A2 //wɛn//

A conjunction used to introduce time clauses indicating when something happens.

When the report is ready, send it to me.

GrammarPoint

if

conjunction CEFR A2 //ɪf//

A conjunction used to express a conditional or possible situation.

If the client agrees, we'll sign the contract.

GrammarPoint

present simple (in time clauses)

verb form CEFR B1 //ˈprɛzənt ˈsɪmpəl//

The present simple is used in subordinate time clauses (with when/if) to refer to future events.

When she arrives, we will start the meeting.

GrammarPoint

present perfect

verb form CEFR B2 //prɪˈzɛnt ˈpɜːrfɪkt//

A verb tense used to indicate an action completed at some point before now or before another action.

When I've completed the review, I'll send you my notes.

Vocabulary

subordinate clause

noun CEFR B1 //səˈbɔːrdənət klɔːz//

A clause that depends on the main clause and cannot stand alone.

When the meeting ends, we will review the action items.

Expression

certainty vs possibility

expression CEFR B2 //sərˈtɛnti vs pɒsəˈbɪlɪti//

The distinction between events expected to happen (certainty) and those that may or may not happen (possibility).

When we receive the payment, we'll confirm the order (certainty).