Select the most appropriate option to fill in the blank.

Yesterday, I ______ to be on a street with a few modest restaurants.

happened

The most appropriate option to fill in the blank is happened.

The word happened is the past tense of the verb happen. It is used to describe something that took place in the past. In this case, the sentence is saying that yesterday, I happened to be on a street with a few modest restaurants. This means that it was by chance or coincidence that I was on that street.

The other options do not make sense in the context of the sentence.

• Have happen is not a grammatically correct phrase.
• Am happening is the present progressive tense of the verb happen. It is used to describe something that is happening now. However, the sentence is about something that happened in the past, so the present progressive tense is not appropriate.
• Happening is the present participle of the verb happen. It is used to form the present progressive tense. However, as mentioned above, the present progressive tense is not appropriate in this context.