B1 Grammar Section First conditional, future time clauses

Use the first conditional for real/likely results in the future.
Use future time clauses with when / as soon as / before / after / until / once / while to talk about future time. No future form inside those clauses.

Comma rule: put a comma after the time/if clause when it comes first. No comma when it comes second.

Pattern	Example
if + present → will + base	If it rains, we’ll stay home.
if + present → modal / imperative	If you finish early, you can leave. • Call me if you need anything.
when/after/etc. + present → will + base	We’ll start when everyone arrives.

We sometimes use present perfect in the time clause to emphasise completion: After you’ve finished, we’ll go.

Real condition The if-clause speaks about a possible situation in the future; the main clause is the result.
Modals in the main clause You may/might/can/should/must use a modal instead of will: If he doesn’t train harder, he might lose.
Imperatives are fine in results: If you’re cold, close the window.

unless = if not: I won’t go on holiday unless I save money.
as long as / provided (that) = condition/requirement: You can borrow it as long as you bring it back tomorrow.
in case = for prevention (not conditional result): Take an umbrella in case it rains. (reason), not *We’ll stay in case it rains → say if.

when, as soon as, before, after, until, once, while

You can use the present continuous in the time clause for arranged future: While you’re driving, don’t text.

Clause type	Verb form inside the clause	Typical result clause
If (real condition)	Present Simple / Present Perfect	will / modal / imperative
When / As soon as / Before / After / Until / Once / While	Present Simple (or Present Perfect)	will / modal / imperative
Unless (= if not)	Present Simple	will / modal / imperative
In case (reason/prevention)	Present Simple	Often imperative or take/bring etc.