Question

Students have left the classroom before the teacher

• A. will enter
• B. has entered
• C. entered
• D. enters

Hint:

Remember the common tense pairings with conjunctions. For instance, "Past Perfect + before + Simple Past" (e.g., They textbf{had left} before she textbf{arrived}) and "Present Perfect + before + Simple Present" (e.g., They textbf{have left} before she textbf{arrives}).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This question tests the rules of tense sequence, particularly how different tenses are used together in a complex sentence with a conjunction like 'before'.
Step 2: Detailed Explanation:
The first clause, "Students have left the classroom," is in the Present Perfect Tense. This tense is used to describe an action that happened in the past but has a connection to the present.
When 'before' is used to connect a Present Perfect clause with another clause, the second clause is typically in the Simple Present Tense to indicate a future event from a present perspective or a general truth.
The correct structure is: Present Perfect Tense + before + Simple Present Tense.
Applying this rule: "Students have left (Present Perfect) the classroom before the teacher enters (Simple Present)."
Step 3: Final Answer:
The correct verb form to complete the sentence according to the rules of tense agreement is 'enters'.