What is the suffix for in what matter?

The phrase "in what matter" doesn't have a specific suffix. It's a complete phrase, not a word with a suffix.

However, if you're asking about similar phrases, you might be thinking of:

* -wise: This suffix is used to turn nouns into adverbs, meaning "in the manner of" or "in the way of." For example, "moneywise," "fashionwise," or "timewise."

* -ly: This suffix is also used to turn adjectives into adverbs, often expressing manner. Examples include "quickly," "slowly," "happily," "sadly."

Let me know if you have any other questions!