'My English is not very good. Can we speak Chinese?'
大概句型是这样, 具体用词可以稍有变化, 下面这些都可以. 前面半句可以换成:
"I'm afraid my English is not very good" 这样的语气稍微更客气些
"I'm sorry my English is not very good" 为英语不好表示道歉, 也表示很客气.
后半句的别的说法:
Can we talk in Chinese?
Do you mind if we speak Chinese?
Do you mind if we talk in Chinese?
Can we use Chinese instead?
Do you mind if we use Chinese instead?
Will it be okay if we talk in Chinese?
类似等等
原句中的'交流'我理解成说话交流, 如果楼主的意思是书面交流,就把'talk/speak' 改成 write