This question is really hard to answer. I can only think of few examples, hope it might help a little bit. Like Shirley said,you said "哇咧" when you are very surprised about something or what other ppl do. You can say "好耶" which just emphasized the word "good"! It doesn't have meaning in this example from my point of view. So 耶 doesn't necessary express your doubt. 喔is similar to 耶! so you say,"好好喔","好可愛喔" "I am going home next week" :好好喔" . Here you show your admiration. As for "這樣喔!?", it's like " is it?" "I am going home next week" . "這樣喔" Here you mean "is it?" or simply express " ok, I got the information" "再說囉","看開點囉"! I am not sure what 囉 means here! Can only give few sentences! >< "再說囉"(We will talk about it later) "看開點囉" (Don't be so pessimistic, cheer up!)

actually they don't mean anything as the words "yo", "ya", "a" you have known. there are lots of modal particles in Chinese such as 啊、啦、呢、吧、了、哇、呀、吗. and popularly used in Taiwanese "哎、耶、啦" In English, questions always have a rising intonation, but in Chinese, just put a "吗" or "呢" at the end of the sentence. 啊，哇，呀：we always use them to explain a feeling for amazement or admiration. ex: 哇，这山好高啊（呀）。她好漂亮呀（呀）。 吧,吗,呢，：they are used in something that not certain. ex: 我去呢？还是他去？一起去吗？不是吧？ others are used in assertive sentences or negative sentences for emphasizing.

Well, actually I think its a bit pretentious if a foreigner speak like that. And those words are all a bit girly btw.

you can try all of them out... and we will tell you if it`s right or not... because it`s really difficult to explain them.

哇咧(驚訝/不可置信語氣/)! 要看句子耶(疑問/質疑語氣)! 如果有實際狀況會更好喔(緩和語氣/可愛語氣)! 就這樣囉(只好如此的感覺)! 其實,要看當時情形,意思又會變呢!