When "however" is used as a conjunctive adverb:
* You do use a comma after "however" if it introduces a contrasting idea. This is like saying, "but..."
* Example: "The weather was terrible, however, we still managed to have a good time."
When "however" is used as an adjective:
* You don't use a comma after "however" if it modifies a noun or pronoun.
* Example: "We were faced with a however difficult situation."
Let's see some examples:
* Comma needed:
* "The movie was long, however, I enjoyed it."
* "I'm not sure I can do this, however, I'll try my best."
* No comma needed:
* "The group discussed the however complex issue."
* "He made a however bold decision."
Here's a simple rule of thumb: If you could replace "however" with "but," then you likely need a comma.