why cheese sandwich = kanapka z serem but herbarta z cytryną =/= lemon tea?
a sandwich doesn't literally have a 'cheese flavour', it is 'with cheese' - in Polish, at least, 'cause English makes it 'a cheese sandwich'.
Tea with a slice of lemon and lemon flavoured tea are often both called lemon tea (in British English, at least).
"You used the wrong word. Do you like tea awith a lemon?" what does "awith" mean?