Adverb Clauses of Time: When, Before, After, Until

Fix the rookie time traveler's manual by dragging the grammatically correct verbs into the time clauses.

The time portal will permanently close as soon as the clock [*strikes*|will strike|struck](?) midnight.

You absolutely must memorize the map before you [*leave*|will leave|left](?) the year 2024.

We will analyze the timeline changes after you [*return*|returned|will return](?) to headquarters.

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The time portal will permanently close as soon as the clock **strikes** midnight.

> Even though the event happens in the future, adverb clauses of time starting with *as soon as* require a present tense verb (**strikes**), not a future tense verb.

You absolutely must memorize the map before you **leave** the year 2024.

> After the time conjunction *before*, we use the present simple tense (**leave**) to refer to a future event.

We will analyze the timeline changes after you **return** to headquarters.

> The main clause is in the future tense ("will analyze"), so the time clause introduced by *after* must be in the present tense (**return**).

