Time Clauses in Conditionals — When, Before, After, Until

Time clauses use conjunctions like when, before, after, as soon as, and until to connect two events in time. The most important rule is that time clauses about the future use present simple, not "will": "When I arrive, I will call you" (not "When I will arrive"). This rule applies to all time conjunctions and is one of the most commonly tested grammar points in English exams from B1 level onwards.

Time clauses work similarly to first conditional if-clauses — both use present simple to talk about future events. The difference is meaning: "if" introduces uncertainty ("If she comes" — she might not come), while "when" implies expectation ("When she comes" — she is expected to come). "Before" and "after" show sequence: "Before you leave, close all the windows." "As soon as" emphasises immediacy: "As soon as I finish, I will call you." "Until" marks the end point: "I will wait until you arrive." Mastering these time conjunctions gives you more precise control over how you describe future plans, instructions, and conditions in both speaking and writing.