我去.....度假了（wo3 qu4 ...........du4 jia4 le)! 我的假期是在.......度过的 （wo3 de jia4 qi1 shi4 zai4 .........du4 guo4 de)! "......." means the place you went Hope this helps!

"我在我的朋友家"is right,if you wanna say where u are ,just say 我在+your location,thats ok.

It's difficult to say because there are many different ways of saying these things in Chinese. If you want to say you were somewhere you'd say "在" here or there: 昨天我在我的朋友家 is pretty good- I'm not sure you need the "的" however, if you went somewhere on vaction you can say "我在中国的（city or other place）度假" as Jasper says. Problem is also is that there are several ways of saying the 度假"vacation" part in Chinese: 度假, (du4jia4), 暑假 (shu3jia (more like summer vacation)), 假期 (jia4qi1), 放假 (fang4jia4).. and more! So you can use any of these words to say you're going to or you've been on vacation!

in Chinese spoken language, 去means 在

当时我在厕所。一看兜里没带纸。只好给Q发短信，让其送纸过来。