Perder el resguardo puede suponer un problema.

Yes. In Spanish, an infinitive can function as a noun-like subject, just like losing in English.

So:

• Perder el resguardo = Losing the receipt/slip
• puede suponer un problema = can mean/cause/be a problem

This is very common in Spanish. Other examples:

• Fumar es malo. = Smoking is bad.
• Llegar tarde molesta. = Arriving late is annoying.

So the whole phrase Perder el resguardo is the subject of puede suponer.

Resguardo is a fairly formal word, especially common in Spain, for a document or slip that serves as proof of something.

Depending on the context, it can mean things like:

• a receipt
• a claim ticket
• a deposit slip
• a proof-of-payment slip
• a collection stub
• a document you must present later

So it is not just any random receipt from a shop. It often suggests an official or practical proof document.

For example, you might get a resguardo when:

• leaving something at a cloakroom
• submitting paperwork
• making a bank deposit
• sending a parcel
• checking in luggage

Using el often means the speaker has a specific kind of document in mind, even if it is being mentioned in a general statement.

So Perder el resguardo puede suponer un problema means something like:

• Losing the receipt/slip can be a problem
• If you lose the receipt/slip, that can cause problems

Spanish often uses the definite article in general statements where English might also use the or sometimes no article at all, depending on style.

Compare:

• Perder el pasaporte es grave. = Losing your passport is serious.
• Romper la llave fue un desastre. = Breaking the key was a disaster.

It does not necessarily mean one unique receipt already mentioned; it can refer to that kind of required document in a general sense.

That is a very common source of confusion.

Suponer can mean different things depending on context:

1. to suppose / to assume

   • Supongo que vendrá. = I suppose he’ll come.

2. to mean / to entail / to involve / to represent

   • Eso supone un riesgo. = That involves a risk.
   • Perder el resguardo puede suponer un problema. = Losing the slip can mean / entail / cause a problem.

In your sentence, suponer does not mean to assume. It means something like:

• to amount to
• to lead to
• to create
• to represent

Because the meaning is softer and more nuanced.

• Perder el resguardo es un problema = Losing the slip is a problem
• Perder el resguardo puede suponer un problema = Losing the slip can cause/become a problem

The version with puede suponer suggests:

• it is a potential consequence, not an absolute fact in every case
• it may depend on the situation
• it sounds a bit more formal or cautious

So this sentence means that losing it may create difficulties, not necessarily that it always does in exactly the same way.

Yes, absolutely. That would be natural and very close in meaning.

The difference is mainly nuance:

• puede ser un problema = simpler, more direct: can be a problem
• puede suponer un problema = slightly more formal, often suggesting can entail / can lead to a problem

In many everyday contexts, both work.

A learner will hear puede ser un problema more often in casual speech, while puede suponer un problema sounds a bit more formal, administrative, or written.

Because Spanish does not need one here. The subject is already the infinitive phrase:

• Perder el resguardo = subject

So the sentence structure is complete without adding anything else.

Spanish often leaves out subject pronouns when the subject is clear, and in this case the subject is not a pronoun anyway: it is the whole action Perder el resguardo.

Yes, it is a general statement. It is not talking about one specific person. It expresses a general truth or warning.

A natural English interpretation is:

• Losing the receipt can be a problem
• If you lose the receipt, that can be a problem

Spanish often uses this kind of infinitive structure for general statements, instructions, and warnings.

It has a neutral, general tone, which is especially common in notices, official language, and informational texts.

Because the sentence is presenting the consequence as a problem in a general sense.

• un problema = a problem
• problemas = problems

Both are possible in different contexts, but singular is very natural here because the idea is broad and non-specific.

Compare:

• Puede suponer un problema. = It can be a problem.
• Puede suponer problemas. = It can cause problems.

The singular version sounds a little more compact and idiomatic in this sentence.

Yes, but the original order is the most natural and neutral.

Standard order:

• Perder el resguardo puede suponer un problema.

You might also see or hear:

• Puede suponer un problema perder el resguardo.

This version is possible, but it sounds a bit more formal or stylistically marked because the infinitive phrase comes later.

For most learners, the original version is the safest and most natural choice.

Yes, resguardo is especially common in Spain, often in formal or administrative contexts.

In other Spanish-speaking regions, people might prefer other words depending on the situation, such as:

• recibo
• comprobante
• ticket
• boleta
• talón

The exact choice depends on the country and the type of document.

So if you are learning Spanish from Spain, resguardo is a very useful word to know, especially for:

• official documents
• collection slips
• proof of submission
• claim tickets

Correct. Here perder means to lose in the sense of no longer having or being unable to find the document.

So:

• Perder el resguardo = to lose the slip/receipt

It does not mean to miss in the sense of failing to catch a train or missing an opportunity, even though perder can also be used in those meanings in other contexts:

• Perder el tren = to miss the train
• Perder una oportunidad = to miss an opportunity

In this sentence, the meaning is clearly to lose/misplace the document.