Meanings (ES + gloss)
aunque
Although; used to introduce a concession; may..but.
He was a great friend, if a little stingy at the bar.
She won her team's admiration, if not the award, for her performance.
si
Whether; used to introduce a noun clause, an indirect question, that functions as the direct object of certain verbs.
I don't know if I want to go or not.
Quoth Matthew, “ […] / She doubts if two and two make four, / […] ”
Phrases
I wouldn't piss on someone if they were on firean ifand ifas ifas if there's no tomorrowbig if truebut ifdamned if I knowelifendifeven ifeven if one's life depended on ithell if I careif I careif I ever saw oneif I mayif I may make so boldif I might be so boldif I were youif I've ever seen oneif all else failsif and only ifif and whenif anythingif at allif clauseif everif ever there has been oneif ever there were oneif ever there were someif it be soif it kills oneif moneyif need beif notif onlyif push comes to shoveif soif so beif that's not