2. Select the word or phrase that makes the following sentence grammatically correct: Why did we try so hard?
Answer: D
We try so hard because we have to.
The sentence is grammatically correct with the phrase "have to," indicating a present obligation or necessity that explains the effort put forth.
A) has to
"Has to" is incorrect in this context because it is singular and would not agree with the plural subject "we." The sentence requires a form that accommodates the plural subject.
B) Haven't
"Haven't" is also incorrect as it is a contraction for "have not," which does not fit the context of the sentence. The original sentence is seeking a phrase that conveys obligation rather than negation.
C) had to
"Had to" is in the past tense, which does not align with the present context of the sentence. The sentence emphasizes a current reason for effort, making "had to" inappropriate.
D) have to
"Have to" is the correct choice as it expresses the present necessity or obligation that justifies the actions taken. It aligns perfectly with the subject "we," making the sentence coherent and grammatically correct.
Conclusion
The correct answer, "have to," effectively conveys the current necessity behind the efforts mentioned in the sentence. All other options fail to maintain grammatical agreement or appropriately express the intended meaning, reinforcing the importance of matching verb forms to their subjects in English grammar.