1. As a conjunctive adverb:
* When it begins a sentence: It *always* requires a comma before it.
* Example: *However, the weather was still beautiful.*
* When it appears in the middle of a sentence: It *usually* requires a comma both before and after it, but not always.
* Example: *The plan was good, however, it didn't account for the wind.*
* Example: *The plan was good however, it didn't account for the wind.* (This is incorrect)
2. As an adjective:
* When it's part of a phrase like "however much," "however many," etc.: It *does not* need a comma before it.
* Example: *However much you love her, you can't always get what you want.*
To be sure, please provide the full sentence you're asking about! 😊