Hahah, you two make me laugh with these posts.
Yoong, all your emoticons and hyper-links work fine for me. I can click on your links and it brings up the post, just like it's supposed to.
About contractions: It depends upon what kind of contraction. Personal pronoun contractions can be used with everything except the simple present, simple past, and past continuous, including most present forms, and all the future forms. They won't work with the simple past, but they can work with the past perfect, and past perfect continuous. However, they can be a bit ambiguous, so you need to write your sentences so they're clear, or write them out to avoid any confusing cases. Also, contractions are viewed as informal, so be aware of the situation you're writing for, when deciding whether or not to use them.
I'd studied acting before moving to New York. (past. perf.)
You weren't studying? (past cont.
but -it's not a personal pronoun contraction.)
You'd been studying when she called. (past. perf. cont.)
I'll do it in a minute( simple future)
I'll have finished it by the time you get home. (future perf.)
However:
He's tired. (Unclear- Is it "He is tired" (simple present), or "He has tired" (pres. perf.)