gimon wo motte iru.

It is read ぎもん を もって いる.

• 疑問 = ぎもん
• を = object particle
• 持っている = もっている

In natural speech, 持っている is often shortened to 持ってる.

を marks 疑問 as the direct object of 持つ.

Here, 持つ does not mean only physically to hold something in your hand. It also commonly means to have in a more abstract sense. So:

• 疑問を持つ = to have a doubt / to have questions / to feel uncertain about something

The structure is:

• 疑問 = doubt, question, uncertainty
• を持つ = to have, to hold

So 疑問を持っている literally looks like is holding a doubt, but naturally means has doubts or has a question/uncertainty.

Because ～ている often shows a continuing state.

With 持つ, the ～ている form often means to be in possession of or to have something as an ongoing state.

So:

• 疑問を持つ = to come to have a doubt / to hold a doubt
• 疑問を持っている = to currently have a doubt / to be holding that doubt as a present state

In many cases, 持っている sounds more natural when talking about someone’s current mental state.

No. Here it is figurative.

Japanese often uses 持つ with abstract nouns, not just physical objects. For example:

• 興味を持つ = to have interest
• 自信を持つ = to have confidence
• 疑問を持つ = to have doubts / questions

So in this sentence, 持っている means has rather than physically is holding.

That is very normal in Japanese. The subject or topic is often omitted when it is understood from context.

So 疑問を持っている。 by itself could mean:

• I have doubts.
• He has doubts.
• She has a question about it.
• They are uncertain.

The actual subject depends on the situation or previous conversation.

If you wanted to state it explicitly, you could say:

• 私は疑問を持っている。 = I have doubts.
• 彼は疑問を持っている。 = He has doubts.

No, they are related but not the same.

• 疑問 = a doubt, uncertainty, something you are unsure about
• 質問 = a question you ask someone

So 疑問を持っている usually means to have doubts or to have something you are unsure about, not necessarily that you are actively asking a question out loud.

For example, someone might 疑問を持っている but not say anything yet.

Sometimes, depending on context, yes.

疑問を持っている often means:

• to have doubts
• to question something
• to be unsure
• to be skeptical about something

For example, if someone says:

• その説明に疑問を持っている。

it could mean:

• I have doubts about that explanation.
• I question that explanation.
• I’m skeptical about that explanation.

So the exact English wording depends on what the doubt is about.

Yes. In Japanese, this can absolutely function as a complete sentence in casual/plain style, especially when the subject and other details are understood from context.

It is a plain-style sentence ending in いる. In more polite speech, you would often say:

• 疑問を持っています。

Both are grammatically fine; the difference is mainly politeness.

Yes, and it is similar, but there is a nuance difference.

• 疑問がある = there is a doubt / I have a question or uncertainty
• 疑問を持っている = I hold doubts / I have doubts

疑問がある is often a bit more neutral and direct. 疑問を持っている can sound a little more like the person has consciously formed that doubt or is maintaining that skeptical feeling.

In many contexts, both are natural.

Here, ～ている shows a current ongoing state, not an action in progress like is doing in English.

With some verbs, ～ている means an ongoing action:

• 食べている = is eating

But with verbs like 持つ, it often describes a resulting state:

• 車を持っている = owns a car
• 疑問を持っている = has doubts

So here it means is in the state of having doubts, not is in the middle of picking up a doubt.

Yes. 持ってる is the casual spoken contraction of 持っている.

So:

• 疑問を持っている = standard full form
• 疑問を持ってる = casual spoken form

Both mean the same thing. The shorter form is very common in conversation.