Identify the part of the sentence that contains a grammatical error.
You must to ensure that (1)/ all parameters are recorded (2)/ before the simulation (3)/ can be rerun. (4)
Show answer & explanation
Correct answer: A
Explanation
Correct Answer: (1)
Explanation
• Part (1) contains an error because modal auxiliary verbs like must, can, should, and may are followed by the bare infinitive (the base form of the verb without to).
• Using the full infinitive (to ensure) after the modal must is grammatically incorrect.
• Correct phrase: "You must ensure that..."
Quick Tip: Modal verbs (must, can, could, will, would, shall, should, may, might) take V1 directly without to (e.g., must go, not must to go).