Em falta un segell per enviar el paquet.

In Catalan, faltar is very commonly used to express the idea that something is missing to someone.

So:

• Em falta un segell literally means A stamp is missing to me
• Natural English: I’m missing a stamp / I need a stamp

This is different from necessito un segell, which also means I need a stamp, but sounds more direct and neutral.
Em falta un segell often feels a bit more like I don’t have one yet or I’m short of one.

So both can work, but em falta is a very natural everyday way to say this.

Em is the unstressed pronoun meaning to me.

In this sentence:

• em = to me
• falta = is missing
• un segell = a stamp

So the structure is:

• Em falta un segell
• literally: A stamp is missing to me

This kind of indirect-object pronoun is very common with verbs like faltar, agradar, quedar, and others.

Compare:

• Em falta un segell = I’m missing a stamp
• Et falta temps = You’re short of time
• Li falta pràctica = He/She needs practice / Practice is lacking for him/her

The verb agrees with the thing that is missing, not with the person affected.

Here, the subject is:

• un segell = a stamp

Since un segell is singular, the verb is singular:

• falta

So:

• Em falta un segell = I’m missing one stamp

If the missing thing were plural, the verb would also be plural:

• Em falten dos segells = I’m missing two stamps

This is one of the most important things to notice with faltar.

Yes. Grammatically, un segell is the subject.

That can feel strange to English speakers, because English usually says:

• I need a stamp

But Catalan organizes it more like:

• A stamp is missing to me

So in:

• Em falta un segell

the roles are:

• em = indirect object (to me)
• falta = verb
• un segell = subject

That is why the verb matches un segell in number.

Here, segell means postage stamp.

In other contexts, segell can also mean:

• seal
• stamp
• an official or institutional stamp/mark

But in the context of enviar el paquet, it clearly means a postage stamp.

So:

• un segell = a stamp
• dos segells = two stamps

In Catalan, per + infinitive is the normal way to express in order to / for the purpose of doing something.

So:

• per enviar el paquet = to send the package / in order to send the package

This is very natural Catalan.

Examples:

• Necessito diners per viatjar = I need money to travel
• Tinc temps per estudiar = I have time to study

You may sometimes encounter per a in other contexts, but before an infinitive, per alone is the standard pattern here.

Yes. That would mean:

• Em falta un segell per poder enviar el paquet
• I’m missing a stamp to be able to send the package

Adding poder makes the idea a little more explicit: the stamp is what makes sending the package possible.

But in most situations, per enviar el paquet already expresses that clearly, so the shorter sentence is more natural.

El paquet means the package, referring to a specific package that the speaker has in mind.

So:

• enviar el paquet = send the package

If you said un paquet, it would sound more indefinite:

• enviar un paquet = send a package

In this sentence, el paquet suggests that both speaker and listener either know which package it is, or the speaker is referring to a particular one in the situation.

The most natural word order is:

• Em falta un segell

That is the standard, everyday way to say it.

You could move things around in Catalan for emphasis, but Un segell em falta sounds marked and unusual in normal conversation. It might be used only in a very special context where you want to strongly emphasize un segell.

So for learners, the best choice is:

• Em falta un segell

Normally, no. Em is essential here because it tells you who is missing the stamp.

• Em falta un segell = I’m missing a stamp
• Et falta un segell = You’re missing a stamp
• Li falta un segell = He/She is missing a stamp

If you just say Falta un segell, that means something more like:

• A stamp is missing
• There is a stamp missing

So without em, the meaning changes.

Mancar can also mean to be lacking / to be missing, so:

• Em manca un segell

is grammatically correct and understandable.

However, faltar is much more common in everyday speech.
Mancar often sounds a bit more formal, literary, or regional, depending on the context.

For most learners, em falta un segell is the safest and most useful everyday phrase.

Yes, absolutely. It sounds natural and idiomatic.

A Catalan speaker might say it when preparing mail and realizing they do not have enough postage:

• Em falta un segell per enviar el paquet.

It is a very normal example of how Catalan uses faltar to express need or lack.

Then both the noun and the verb would become plural:

• Em falten dos segells = I’m missing two stamps

So compare:

• Em falta un segell = I’m missing one stamp
• Em falten dos segells = I’m missing two stamps

This is a very useful pattern:

• Em falta...
  • singular noun
• Em falten...
  • plural noun

Yes, very often that is the implication.

Because the sentence says:

• Em falta un segell

it usually suggests that the speaker is short by exactly one stamp. In context, it often means:

• I just need one more stamp

So besides the basic meaning, it can carry the practical idea that everything else is ready, but one stamp is still missing.