I was wondering if you would mind explaining how -서 changes the word/sentence, like 귀여워 vs 귀여워서? that was the only example I could think of right now, but I see it added fairly often and it got me confused/curious

-아/어서 means "because"! many grammatical concepts in korean are made by conjugating the verb or adjective~ so 귀여워 just means "cute," but "귀여워서" means "because (subject is) cute"