Ne raccroche pas encore, j’ai une dernière question à te poser.

Because raccroche is in the imperative, the form used for commands and requests. In French imperatives, the subject pronoun is normally left out.

• Tu raccroches = you hang up
• Raccroche ! = hang up!
• Ne raccroche pas ! = don’t hang up!

So the missing tu is completely normal here.

Because this is the tu imperative of an -er verb.

For most -er verbs, the tu form of the imperative drops the final -s:

• Tu parles → Parle !
• Tu regardes → Regarde !
• Tu raccroches → Raccroche !

That is why you get Ne raccroche pas and not Ne raccroches pas.

A useful exception: the -s comes back before y and en:

• Vas-y
• Manges-en

French negative commands usually follow this pattern:

Ne + verb + pas

So:

• Raccroche ! = Hang up!
• Ne raccroche pas ! = Don’t hang up!

Then encore is added after that to give the idea of not yet / not just now:

• Ne raccroche pas encore = Don’t hang up yet

In very informal spoken French, people often drop ne and say Raccroche pas encore, but the full form with ne is the standard one.

Here encore means yet.

So Ne raccroche pas encore is literally something like Don’t hang up yet.

This word can mean several things depending on context:

• again: Encore !
• still: Il est encore là
• yet: pas encore

In this sentence, because it follows a negative command, pas encore clearly means not yet.

Yes. Raccrocher is the normal everyday verb for to hang up in a phone context.

Originally it literally suggests putting the receiver back, but it is still the standard modern verb even for mobile phones.

Examples:

• Je raccroche. = I’m hanging up.
• Ne raccroche pas. = Don’t hang up.
• Il m’a raccroché au nez. = He hung up on me.

A learner may notice accrocher also exists, but for phone calls raccrocher is the usual choice.

Because une dernière question means one last question.

It introduces one more question without implying a specific previously identified final question from a list.

• une dernière question = one last question
• la dernière question = the last question

So in this sentence, une dernière question sounds natural because the speaker is just saying they have one more thing to ask.

This is a very common French pattern:

avoir + noun + à + infinitive

It often corresponds to English to have something to ...

Examples:

• J’ai quelque chose à dire. = I have something to say.
• J’ai un travail à finir. = I have a job to finish.
• J’ai une dernière question à te poser. = I have one last question to ask you.

So à te poser describes what kind of question it is: a question that I want to ask you.

The verb pattern is:

poser une question à quelqu’un = to ask someone a question

So:

• Je pose une question à Marie
• Je te pose une question = I ask you a question

When French uses an infinitive, object pronouns usually go before the infinitive:

• à te poser
• pour te voir
• sans lui parler

So te means to you, and à te poser means to ask you.

Because te is the unstressed object pronoun used with the verb.

French uses:

• toi after prepositions when it stands alone: pour toi, avec toi
• te when it is attached to the verb structure: je te parle, te voir, à te poser

Here the pronoun is part of the verbal phrase te poser, so te is the correct form.

Yes. Poser often means to put / to place, but in the expression poser une question, it means to ask a question.

This is just a fixed, very common French expression.

So:

• poser un livre sur la table = put a book on the table
• poser une question = ask a question

It is one of those verb combinations that learners simply need to get used to.

Yes, absolutely. Je veux te poser une dernière question is grammatical and natural.

The difference is mostly in tone:

• J’ai une dernière question à te poser sounds very natural and slightly more idiomatic in this context.
• Je veux te poser une dernière question is more direct: I want to ask you one last question.

Both work, but the original sentence feels especially smooth and conversational.

Because je becomes j’ before a vowel sound.

So:

• je ai is not used
• j’ai is the correct form

This is called elision.

You see the same thing in:

• j’aime
• j’habite
• j’écoute

In the same sentence, ne does not contract because raccroche starts with a consonant, so it stays ne raccroche pas.