Can you swear to his _______ in your house that evening? (Fill in the blank with the appropriate option.)
A) been
B) to have been
C) to be
D) having been

Hint: A sentence or phrase is the basic language unit that represents a full idea. This is done in compliance with the simple grammatical syntax guidelines. There is at least one subject and one main verb present in a complete sentence to declare a complete thought.

Complete answer:
A verb is a word that expresses an action, an occurrence, or a state of being through syntax. The infinitive is the most basic form in English, and it can be used with or without a particle. Verbs are inflected in several languages to indicate tense, aspect, mood, and voice.

The present perfect continuous tense (also known as the present perfect progressive tense) expresses the fact that something began in the past and is still going on now. In the above sentence, we have to use the present perfect continuous tense to show the action that someone has been in his house.

Let’s go through the options:
Option A) been: This option is incorrect because been is the past tense of ‘be’ but in the above sentence we have to use the present perfect continuous sentence, hence we cannot use this option.

Option B) to have been: This option is incorrect because it would make the sentence grammatically incorrect and also because it is in present perfect tense whereas the above sentence requires present perfect continuous tense.

Option C) to be: This option is incorrect because ‘to be’ is simple present tense whereas the above sentence requires the use of present perfect continuous tense.

Option D) having been: This is the correct answer. ‘Having been’ is a present perfect continuous tense; it's used to emphasize that the primary action has been completed before the second act begins. In the above sentence, the person has already been to his house before he was asked to swear to it.

Therefore, the correct answer is option D) having been. “Can you swear to his having been in your house that evening?”

Note: The perfect participle is formed by combining the word having with a word's past participle. Perfect participles show that a task has been done in the past. Examples: having watched, having arrived, and having slept.