Is there a name for when you answer in complete sentence using words from the question itself?

There isn't a specific, widely recognized name for answering in complete sentences using words from the question itself. However, you could describe it as:

* Echoing the question: This emphasizes the use of the original words in the answer.

* Paraphrasing with key terms: This focuses on the semantic connection between question and answer.

* Using the question's vocabulary: This highlights the specific word choice in the answer.

You could also use more informal terms like:

* Playing word games: This is a playful way to describe the use of the question's words.

* Being clever: This implies a deliberate and skillful use of the question's language.

Ultimately, the best way to describe this type of answer depends on the specific context and the desired tone.