No quiero posponer otra vez la reunión sobre mi expediente, porque el plazo termina el lunes.

Because after querer (to want), Spanish normally uses an infinitive.

• quiero posponer = I want to postpone
• not quiero pospongo

So the pattern is:

• querer + infinitive
• No quiero salir
• Queremos hablar
• No quieren esperar

In your sentence, No quiero posponer otra vez... means I don’t want to postpone again...

Posponer means to postpone, to put off, or to delay until later.

It is a correct and fairly common word, especially in more formal or neutral Spanish. In everyday speech, learners may also hear:

• aplazar = to postpone
• retrasar = to delay

The differences are small here:

• posponer la reunión = postpone the meeting
• aplazar la reunión = postpone the meeting
• retrasar la reunión = delay the meeting

In this sentence, posponer sounds perfectly natural.

Yes, both are possible.

• otra vez = again
• de nuevo = again / anew

So these both work:

• No quiero posponer otra vez la reunión
• No quiero posponer de nuevo la reunión

In many contexts, they mean almost the same thing. Otra vez is very common and conversational. De nuevo can sound a little more formal or stylistically smoother, depending on the context.

Sobre means about / concerning, so la reunión sobre mi expediente means the meeting about my file/case.

That is a very natural choice because the meeting is about that topic.

You might also hear:

• la reunión acerca de mi expediente
• la reunión sobre mi expediente

Using de would usually sound less clear here. La reunión de mi expediente is not the most natural way to express the meeting about my file.

So for topic or subject matter, sobre is a good choice.

In Spain, expediente often refers to an official file, record, or case file, especially in administrative, academic, legal, or bureaucratic contexts.

Depending on the situation, it could refer to:

• a university record
• a government application file
• a disciplinary record
• an immigration or legal case file

So mi expediente does not usually mean a random folder of papers in a casual sense. It often suggests an official dossier or case record.

Both can relate to deadlines, but they are not exactly the same.

• plazo = a period of time allowed for something, or the deadline period
• fecha límite = the final date itself

So:

• El plazo termina el lunes = The deadline period ends on Monday
• La fecha límite es el lunes = The final date is Monday

In bureaucratic or formal contexts, plazo is extremely common in Spain. It often appears in phrases like:

• dentro del plazo = within the deadline
• fuera de plazo = after the deadline / too late
• ampliar el plazo = extend the deadline

Spanish often uses the present tense to talk about future events when they are scheduled, fixed, or clearly expected.

So:

• el plazo termina el lunes

means something like:

• the deadline ends on Monday

This is very natural in Spanish, just like in English when we say:

• The train leaves tomorrow
• The course starts on Monday

You could also say:

• el plazo terminará el lunes

but termina sounds very normal and idiomatic here.

In Spanish, when talking about days of the week for when something happens, you usually do not use a preposition like on.

So English says:

• on Monday

but Spanish says:

• el lunes

Examples:

• Llego el martes = I arrive on Tuesday
• La reunión es el jueves = The meeting is on Thursday
• Termina el lunes = It ends on Monday

So el lunes is the normal structure.

Because porque is the conjunction meaning because.

• porque = because
• por qué = why

So in this sentence:

• ..., porque el plazo termina el lunes.
• ..., because the deadline ends on Monday.

Compare:

• No fui porque estaba enfermo. = I didn’t go because I was ill.
• ¿Por qué no fuiste? = Why didn’t you go?

This is a very common spelling distinction in Spanish.

In Spanish, the most natural way to negate querer is to put no before the conjugated verb:

• No quiero posponer... = I don’t want to postpone...

If you said:

• Quiero no posponer...

it would sound more like:

• I want not to postpone...

That structure is possible in some contexts, but it is much less natural here. For a simple I don’t want to..., Spanish normally uses:

• No quiero + infinitive

Yes, absolutely. That is a very natural alternative.

• No quiero posponer otra vez la reunión
• No quiero volver a posponer la reunión

Both mean I don’t want to postpone the meeting again.

A small difference in feel:

• otra vez directly says again
• volver a + infinitive literally means to do something again

Examples:

• Volví a llamar = I called again
• No quiero volver a esperar = I don’t want to wait again

In many cases, either option sounds good.

Each one works a little differently:

• la reunión: a specific meeting, not just any meeting
• mi expediente: possessive already makes it specific, so no article is needed before mi
• el plazo: a specific deadline or time limit already known in the context

So:

• la reunión = the meeting
• mi expediente = my file/case
• el plazo = the deadline

Spanish often uses articles more than English does, especially when referring to something known or established in the situation.

It sounds mostly neutral, with a slightly formal/administrative feel because of words like expediente and plazo.

Parts of the sentence are very everyday:

• No quiero...
• otra vez
• el lunes

But these words add a more official tone:

• expediente
• plazo
• posponer

So it would fit well in:

• workplace Spanish
• university administration
• government or legal contexts
• polite conversation about paperwork or appointments

It does not sound overly stiff, but it does sound more serious than purely casual speech.