I hope Americans can speak Chinese, can learn Chinese.
我希望美国人能够说汉语，能够学习汉语。
I am an American but I can speak Chinese.
我从美国来的不过我会说中文。
In China, we speak Chinese.
在中国，我们说汉语。
My parents don't speak chinese, they speak english.
我父母亲不讲中文，他们讲英语。
We must not speak Chinese in our English lessons.
我们不可在我们的英语课过程中讲汉语。