"I bought an iphone just so that i can learn mandarin" "我买了个Iphone就是因为我能学普通话" I guess, probably you wanted to say, "I bought an Iphone just so that I can use it to learn mandarin" "我买了个Iphone就是因为我能用它学普通话"

I bought an iphone just so that I can learn Mandarin. 我买了iphone，只是为了便于我学习普通话。I changed some words in order to make it in a natural way. so that = 以便；以至于 so = 所以

I agree with Nicole 我买了iPhone 因为我想学习中文 因为 = because, this should be replaced with 所以 = so that, 想 = want, this should be replaced with 可以 = can, 学(习) = you can eliminate the 习 if you desire 中文 = means Chinese, if you want to say Mandarin specifically use 普通话

I dont think so. "I bought an iphone just so that i can learn mandarin" /= 我买了iPhone，因为我想学习中文 ? Is 我买了iPhone，我才能够(可以)学习中文。 Opposite, I can learn mandarin just so that "I bought an iphone =我买了iPhone，因为我想学习中文 .... I think so.

我买了一部Iphone手机，那样的话我就可以学习普通话了！