"You like eggs, and they like mayonnaise."
Translation:Ти любиш яйця, а вони люблять майонез.
It's all about the agreement between the subjects, verbs and objects of the two sentences you want to connect:
Ти любиш макарони, і ти любиш/ненавидиш рис (the subject is the same, so nothing else matters)
Ти любиш макарони, і вона любить макарони (both love; both love pasta)
Ти любиш макарони, а вона ненавидить (hate) макарони (both are about pasta, but the action is different)
Ти любиш макарони, а вона любить рис (the action is the same, but the object is different)
"а" is used when two things are being contrasted. Some examples of typical uses:
- I am an X and you are a Y (eg. Я директор, а ти актор)
- He does X and they do Y (eg. Він читає, а вони пишуть)
- Bob is/does an X, not an Y (eg. Тато — програміст, а не актор)
- And you? (А ти?)
And so on.
In all of these situations using «і» would be incorrect because you use it only to connect sentences about similar things, not the things that do not match.
«Та» has a somewhat broader use but I doubt it is possible here either (let a native speaker correct me if I'm wrong).
Plural/singular "you". The plural one is also used to politely address one person—basically, what you use to address a stranger (unless you are talking to a child), a teacher, or a person with whom you are otherwise not on friendly terms.
- gods and demons are not addressed politely (good luck in your conversations!)