Justement, je voulais te parler de ce problème.

Here justement is an adverb that adds a nuance like actually, as a matter of fact, that’s exactly the point, or funny you should mention that.

In this sentence, it often suggests that what follows is especially relevant to the conversation. It is not just precisely in a mathematical sense; it can also sound like:

• That’s exactly what I wanted to talk to you about.
• As a matter of fact, I wanted to talk to you about that problem.

So justement often connects your sentence to something that was just said.

Je voulais is the imperfect form of vouloir. French often uses the imperfect here to sound less abrupt or less direct than je veux.

Compare:

• Je veux te parler = I want to talk to you
  This is direct and very present-focused.
• Je voulais te parler = literally I wanted to talk to you, but in real use it can sound softer, more natural, and less forceful.

So even if the speaker still wants to talk now, je voulais may be used as a polite or gentle way to introduce the topic.

No. That is a very common learner question.

In English, I wanted to talk to you can also be a soft way of saying I want to talk to you now, and French works similarly here.

So je voulais te parler can mean:

• a past intention: the speaker had wanted to talk earlier
• or a softer present intention: the speaker is bringing it up now in a less direct way

The exact meaning depends on context and tone.

Because in French, object pronouns usually go directly before the verb they belong to, and with an infinitive they usually go before the infinitive.

So:

• parler à toi becomes te parler
• Je voulais te parler = I wanted to talk to you

This is the same pattern as:

• Je vais te voir = I’m going to see you
• Je peux lui écrire = I can write to him/her

So te comes before parler, not after it.

Te is an unstressed object pronoun. Toi is a stressed pronoun.

In this sentence, French needs the unstressed form:

• Je voulais te parler = correct

You use toi in other situations, for example:

• after a preposition: avec toi
• for emphasis: Toi, tu comprends
• by itself: Moi ? Toi ?

So here te is required because it functions as the object pronoun linked to parler.

Because parler often works with this pattern:

• parler à quelqu’un de quelque chose

That means:

• to speak to someone about something

So in your sentence:

• te = to you
• de ce problème = about this problem

The full structure is:

• Je voulais te parler de ce problème.

That is the normal way to say I wanted to talk to you about this problem.

Because du is the contraction of de + le.

But here the word after de is not le. It is ce, the demonstrative adjective meaning this or that.

So:

• de + le problème → du problème
• de + ce problème → de ce problème

There is no contraction with ce.

Yes, problème is masculine, even though it ends in -e.

So:

• ce problème = this problem

French gender does not always match the ending of the word. A final -e does not automatically make a noun feminine.

Also, it is ce and not cet because problème begins with a consonant sound.

Compare:

• ce problème
• cet accident
• cet homme

So the form here is correct: ce problème.

Yes. If you are speaking formally to one person, or to more than one person, you would say:

• Justement, je voulais vous parler de ce problème.

So:

• te = informal singular you
• vous = formal singular you or plural you

The rest of the sentence stays the same.

That would change the meaning quite a bit.

• Je voulais te parler suggests an intention, background, or a softer introduction.
• J’ai voulu te parler sounds more like I wanted to talk to you as a completed past event.

Very often, j’ai voulu can suggest that the wanting happened at a specific moment, and sometimes even that the action did not happen or was interrupted.

So in this kind of sentence, je voulais te parler is usually the more natural choice if you are introducing a topic gently.