1 The verb “有” can be used together with both. (有疑问 有问题 both correct) The verb "问" can only be used together with 问题（问问题）（问疑问 sounds weird） 2 问题 is just like a question. When you have a 问题 for me, maybe you don't know the answer, so you wish to find the answer by asking me the question. But it's also possible that you do know the answer and just want to test me. 疑问 sometimes can be a question, but it must be a question with doubt. When I have a 疑问, that means I just don't know the answer. for example: 老师问了我一个问题。（The teacher asked me a question.） It's not proper here to use 疑問，because the teacher is supposed to know the answer. 我有一個問題/疑問：你为什么不愿意结婚？ (I have a question: Why don't you want to get married?) In this sentence, 问题 and 疑问 are both correct. “疑問” is just to emphasize the doubt. hope it helps ^^

我對這個結果充滿疑問. 我對你的服裝有疑問. 我對XXXXXX有疑問 馬航失蹤網民提5大疑問早猜到涉劫機 So 疑問 = The question you don't know and want to know. 我有一些問題想要問你. 我覺得這個東西有問題. 回答我的問題. 問題的答案. 問題 = Questions which is for asking.

补充上面的答案： 有的句子中“问题"是有“不好的感觉”（我理解你想表达的意思是“贬义”）。 比如说“你脑子是不是有问题？”（有问题=有病），这是很不礼貌的话。 “资金是不是有问题”(有问题=遇到了困难) “你的健康是不是出了问题”（你是不是生病了） 但是“疑问”通常是一个很普通的词，就是question而已

疑問=doubt 問題=question but 問題can also mean problem. Mostly used as 有問題 ex: 我對()有疑問 not 我對()有問題 while 我有個疑問=我有個問題 if you wanna say he's got a problem it would be 他有點問題 hope that helps

What's the matter,problem?问题 What's the question? 疑问/问题