คุณอาจจะตอบคำถามของฉันไม่ได้ทั้งหมด
ดังนั้นคุณควรจะบอกว่าฉันสามารถถามอะไรคุณได้บ้าง
You may answer my question, not at all.
So you should say I can ask you?
You may have to answer my question.
So you should be able to tell you that I ask you?
You may not have all the answers to my questions
, so you should be told that I can ask what you can do.