Question

Correct the error in the underlined part of the sentence.
I would have waited for you at the station if I knew that you would come.

• A. Had known
• B. Was knowing
• C. Have known
• D. No improvement

Answer 1

The correct option is A Had known

Let’s examine the sentence: “I would have waited for you at the station if I knew that you would come.” The sentence uses the third conditional. The third conditional is used to talk about 'impossible' conditions. They are impossible because they happened in the past and we cannot change them.
It is formed in the following way:
Would have + past participle + if + past perfect
So, verbs of past perfect tense would be used after “if.” So, “knew” would be replaced by “had known.” The correct sentence would be, “I would have waited for you at the station if I had known that you would come.” So, Option A is the correct answer.