On a different page a course moderator explained that they are the same, but that you would want to avoid using "i" if the next word started with an "a" or an "i".
No difference whatsoever, in Ukrainian there are several words for "and" purely for the purpose of sounding melodic.
Actually, we also have "й", yet another form of "and", for the case when both words "meet" with vowels. We use these different forms so that the phrase rolls easily from your tongue, with no vowels or consonants clashing.
consonant-consonant: брат і сестра [brat i sestra] (brother and sister)
vowel-vowel: Олена й Олександр [Olena j Oleksandr] (two names)
vowel-consonant: : мама та тато [mama ta tato] (mother and father)
As someone who knows some Swedish, I always think "thanks" when I see the word Tak. :p
And, yes, I know I wrote that without a cryllic keyboard, I need to download it.
"Tak" also means "Yes" in Polish.
If you're on a Windows computer, you probably already have the keyboards; you just have to enable them, and use shift+alt to switch between keyboards: http://windows.microsoft.com/en-ca/windows-8/add-language-keyboard
Other operating systems probably have similar features.
А чого нема артіклей the dad and the mom are there or A mom and a dad are there???