tā gǎn wèn wèntí.

The pattern is:

Subject + 敢 + Verb + Object

So here:

• 他 = subject
• 敢 = dare to / be brave enough to
• 问 = ask
• 问题 = question(s)

So 敢 comes before the main verb 问, and 问题 is the thing being asked.

敢 means to dare to, to have the nerve to, or to be brave enough to.

In this sentence, it suggests courage or boldness. It is not just a neutral can.

Compare:

• 他敢问问题。 = He dares to ask questions.
• 他会问问题。 = He knows how to ask questions.
• 他能问问题。 = He is able/allowed to ask questions.

So 敢 focuses on courage, not ability.

Also, depending on tone and context, 敢 can sometimes sound a little marked in English, like he actually dares to ask questions or he has the nerve to ask questions.

Yes, but they do different jobs:

• 问 is a verb: to ask
• 问题 is a noun: question; problem

So 问问题 literally means ask questions.

This kind of repetition is completely normal in Chinese. It is similar to English patterns like:

• dream a dream
• smile a smile
  though ask questions is much more natural and common in English.

So 问问题 is not wrong or strange just because both parts relate to questions.

Because Chinese does not need it here.

In English, we say dare to ask.
In Chinese, modal or modal-like verbs such as 敢, 会, 能, 想, 要 usually go directly before the main verb:

• 敢问
• 会说
• 能去
• 想吃

So 敢问问题 is the normal structure. There is no extra word equivalent to English to.

Here it means question.

问题 can mean either:

• question
• problem

The context tells you which one is meant.

After the verb 问 (to ask), it naturally means question:

• 问问题 = ask questions

But in other contexts, it may mean problem:

• 有问题 = there is a problem / there are problems
• 这个问题很严重。 = This problem is serious.

So in this sentence, 问题 is definitely understood as question(s).

It can be either, depending on context.

Chinese nouns usually do not show singular/plural the way English does. So 问题 by itself can mean:

• a question
• questions
• the question(s)

In this sentence, English will often translate it as questions because that sounds natural: He dares to ask questions.

If you want to make it clearly singular, you can say:

• 一个问题 = one question

If you want to make it clearly plural, you can say:

• 很多问题 = many questions

Chinese often leaves out information that is obvious or not important.

In 他敢问问题, the listener is not stated. The sentence only says that he dares to ask questions.

If you want to say who he asks, you can add it:

• 他敢问老师问题。 = He dares to ask the teacher questions.
• 他敢向老师问问题。 = He dares to ask the teacher questions.

So the original sentence is fine, but it leaves the listener unspecified.

Yes, it is grammatical and understandable. But by itself, it can feel a little context-dependent.

For example, it sounds natural in a situation like:

• a shy student versus a confident student
• someone speaking up in class
• someone boldly asking about something others are afraid to ask

Depending on what you want to emphasize, native speakers might also say:

• 他敢问。 = He dares to ask.
• 他敢问老师问题。 = He dares to ask the teacher questions.
• 他敢提问题。 = He dares to raise questions.
• 他敢发问。 = He dares to ask / speak up with questions.

So the sentence is fine, but in real conversation people often add more context.

No. It may look repetitive to an English speaker, but it is very normal in Chinese.

This is because:

• 问 = the action ask
• 问题 = the thing being asked, question

So 问问题 is a standard verb-object phrase.

Chinese often uses combinations like this, even if the meanings are closely related.

It is pronounced:

tā gǎn wèn wèntí

Tones:

• 他 tā — first tone
• 敢 gǎn — third tone
• 问 wèn — fourth tone
• 问题 wèntí — fourth tone + second tone

A few notes:

• 问题 is a two-syllable word: wèn-tí
• The two wen syllables are different words:
  • 问 = wèn
  • the first syllable of 问题 = wèn
• In natural speech, gǎn before a fourth-tone syllable often sounds like a lower, shorter third tone rather than a full dipping tone

You put 不 before 敢:

• 他不敢问问题。 = He does not dare to ask questions.

This is the normal pattern:

Subject + 不敢 + Verb

Examples:

• 我不敢说。 = I don’t dare speak.
• 她不敢去。 = She doesn’t dare go.

There are two very common ways:

1. Add 吗:

   • 他敢问问题吗？ = Does he dare to ask questions?

2. Use the A-not-A pattern:

   • 他敢不敢问问题？ = Does he dare to ask questions?

The second one is very common in spoken Chinese.

You would usually say:

• 问一个问题 = ask one question

So:

• 他敢问一个问题。 = He dares to ask a question.

This is clearer if you mean a single question.
The original 问问题 is more general and often feels like ask questions as a habit or behavior.