"Well, it's that I understand your English, but..."
This phrase is often used to soften a criticism or disagreement after acknowledging that you understand what the other person is saying. It's a way of saying, "I get what you're saying, but..."
Here's an example:
* You: "I think you should study more."
* Friend: "Pues es que yo entiendo tu inglés pero, I have a lot going on right now."
In this example, the friend acknowledges that they understand what the other person is saying, but they have a reason for not studying more.