Question 197·Medium·Form, Structure, and Sense
The coastal engineers _____ the seawall for several months before the first major storm of the season struck, allowing them to identify and repair weak points in the structure.
Which choice completes the text so that it conforms to the conventions of Standard English?
For verb tense questions, always read the entire sentence and anchor yourself with clear time clues (like "before," "after," specific past events, or time durations such as "for several months"). Decide the timeline: is the action ongoing, completed, or happening before another past event? Then eliminate any choices whose tense does not match that timeline or that shift the sentence into the wrong time (like present or present perfect when everything else is past). Finally, check that the subject is logically doing the action (active voice) unless there is a clear reason to use passive voice.
Hints
Pay attention to time markers
Look closely at the phrases "for several months" and "before the first major storm of the season struck." What do they tell you about when the action happened?
Compare the verb forms with the rest of the sentence
The verb "struck" is in the past tense. Should the missing verb describe something happening now, something linked to now, or something that was happening in the past before that storm?
Check who is doing the action
Is someone watching the engineers, or are the engineers watching something? Use that to decide whether you need an active or passive verb form.
Step-by-step Explanation
Identify what the question is testing
This question is about verb tense and voice. You need to choose the verb form that best fits the time relationship in the sentence and matches the subject "The coastal engineers."
Use the time clues in the sentence
Focus on the phrases "for several months" and "before the first major storm of the season struck".
- "For several months" suggests an ongoing action over a period of time.
- "Before the first major storm of the season struck" refers to a specific event in the past. So the engineers’ monitoring happened over time and finished before that past event (the storm striking).
Match the tense to the time relationship
You want a verb form that shows an ongoing action in the past that continued up until another past event.
- Simple present (like "monitor") does not fit because the storm “struck” is clearly in the past.
- Present perfect (like "have monitored") usually connects the past to the present, but the whole sentence is anchored in the past.
- A passive form (like "were monitored") would mean the engineers are the ones being watched, which does not fit the meaning of the sentence. Only one option shows an ongoing past action that was happening for months before another past event and keeps the engineers as the ones doing the action.
Select the verb that fits both meaning and grammar
The only choice that expresses an ongoing action that happened for several months and was already in progress before the storm struck, while keeping the engineers as the ones doing the action, is "had been monitoring". So the completed sentence is:
"The coastal engineers had been monitoring the seawall for several months before the first major storm of the season struck, allowing them to identify and repair weak points in the structure."