Learn a little bit of linguistics.
I'd be interested if you were to expand on this.
I'm not the OP of that comment, but as a linguistics student I can corroborate. I think there are a couple of reasons that occasionally throwing a relevant piece of linguistic information into a conversation can produce the smartness impression. Firstly, conversations never fail to involve language, so opportunities to comment on language are practically constant if you're attuned to noticing interesting bits and pieces. This means that even occasional relevant comments mean you're saying something interesting and relevant quite frequently. This is an adva...
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
(I plan to make these threads from now on. Downvote if you disapprove. If I miss one, feel free to do it yourself.)