Answer:
Interrogative sentence.
Step-by-step explanation:
An interrogative sentence is elucidated as the sentences that put up a question and is marked by the question mark at the end of the sentence. Such sentences are characterized by an inversion of the verb phrase and the subject.
As per the question, the given statement('what is his name again?') exemplifies an 'interrogative sentence' as it puts up a question. The question is reflected through the inclusion of the verb 'is' which precedes the subject('name') and the use of 'what' further compliments and justifies the asking of a question in the sentence. Thus, it demonstrates an 'interrogative sentence.'