Encara que arribi tard, guarda el comprovant de compra.

Encara que means even if or although, depending on context.

In this sentence, it introduces a concession: something should still be done despite another fact.

• Encara que arribi tard = Even if it/he/she arrives late
• guarda el comprovant de compra = keep the proof of purchase / receipt

So the idea is: regardless of the delay, keep the receipt.

A useful distinction:

• encara on its own often means still / yet
• encara que is a fixed expression meaning even if / although

Because after encara que, Catalan often uses the subjunctive, especially when the situation is uncertain, hypothetical, or not presented as a simple fact.

So:

• arribi = subjunctive
• arriba = indicative

Here, Encara que arribi tard means Even if it arrives late, which is a hypothetical possibility, so the subjunctive fits naturally.

Compare:

• Encara que arribi tard, guarda el comprovant.
  Even if it arrives late, keep the receipt.

If you used arriba, it would sound less natural in this kind of sentence.

Arribi is the 3rd person singular form, so it can mean:

• he arrives
• she arrives
• it arrives
• occasionally you in a formal sense, depending on context

Catalan often leaves the subject unstated when it is understood from context.

So in this sentence, the subject is not named. It could refer to:

• a package
• an order
• a product
• a person

The sentence itself does not specify; the context would tell you.

Yes. Guarda is the informal singular imperative of guardar (to keep, to save, to store).

So it is used when speaking to one person in an informal way:

• Guarda el comprovant de compra.
  Keep the proof of purchase.

Other possibilities would be:

• Guardi el comprovant de compra. = formal singular
• Guardeu el comprovant de compra. = plural / polite plural, depending on dialect and usage

So guarda is the equivalent of telling one person: Keep it.

Because Catalan, like Spanish and other Romance languages, often omits subject pronouns when the verb ending already shows who the subject is.

So instead of saying:

• Tu guarda...

Catalan normally just says:

• Guarda...

The verb form already tells you it is addressed to you (informal singular).

In fact, adding tu would usually sound marked or emphatic unless you specifically want contrast:

• Tu guarda el comprovant, no ell.
  You keep the receipt, not him.

Comprovant de compra means proof of purchase.

Depending on context, in English that could be:

• receipt
• proof of purchase
• purchase receipt

Word by word:

• comprovant = proof, voucher, receipt, supporting document
• de compra = of purchase

So el comprovant de compra is the document that proves you bought something.

Because tard here is an adverb, meaning late.

• arribar tard = to arrive late

Examples:

• Ha arribat tard. = He/She arrived late.
• El paquet arriba tard. = The package arrives late.

By contrast, tarda is usually a noun meaning afternoon:

• a la tarda = in the afternoon

So in this sentence:

• arribi tard = arrives late

not anything related to afternoon.

The comma separates the subordinate clause from the main command.

Structure:

• Encara que arribi tard = subordinate clause
• guarda el comprovant de compra = main clause

So the comma helps show:

Even if it arrives late, keep the proof of purchase.

This is very similar to English punctuation in the same structure.

Yes, in many contexts encara que can be translated as either even if or although.

In this sentence, even if is often the more natural choice because the idea sounds conditional or hypothetical:

• Even if it arrives late, keep the receipt.

But although may also work in some contexts:

• Although it arrives late, keep the receipt.

The difference is mainly one of nuance:

• even if = stronger sense of possibility or condition
• although = stronger sense of concession about something viewed more as a fact

Catalan encara que can cover both.

Sometimes yes, but keep is the safest translation here.

Guardar can mean:

• keep
• save
• store
• put away

In the context of a receipt / proof of purchase, English most naturally says:

• keep the receipt
• save the receipt

Both are possible, but keep is especially common and neutral.

Yes, it is perfectly standard Catalan.

Everything about it is normal and idiomatic:

• encara que
  • subjunctive
• arribi tard
• imperative guarda
• el comprovant de compra

A native speaker would understand it immediately.

Yes. A few natural alternatives are possible, depending on style and context:

• Encara que arribi tard, guarda el tiquet.
  Here tiquet is more like ticket/receipt, often used in everyday speech.

• Encara que faci tard, guarda el comprovant de compra.
  This can work if the idea is more like even if it’s late or even if it ends up being late, though it is slightly different in nuance.

• Si arriba tard, guarda igualment el comprovant de compra.
  If it arrives late, keep the proof of purchase anyway.

But the original sentence is already natural and clear.