Here's why:
* "To" is unnecessary: You don't need the preposition "to" after "ask."
* "A correct grammar" is awkward: "Grammar" is a concept, not a countable noun. You can't have "a" grammar, but you can have a specific grammatical rule or structure.
Here are some ways to correct the sentence:
* "Will you ask about correct grammar?" (This is the most natural way to ask the question.)
* "Will you ask for a grammatical correction?" (This is a more specific question about correcting something.)
* "Will you ask about grammar?" (This is a general question about grammar.)
Let me know if you have any other sentences you'd like to check!