Se tiveres um cupão, dá para comprar esta caneta mais barata.

Tiveres is the future subjunctive of ter for tu.

In European Portuguese, after se when you mean if in a possible future situation, Portuguese often uses the future subjunctive:

• Se tiveres um cupão... = If you have a coupon...
• not usually Se tens... in this meaning

This is very common in Portuguese:

• Se fores, avisa. = If you go, let me know.
• Se puderes, ajuda-me. = If you can, help me.

So tiveres does not literally mean a different English tense here; it is just the normal Portuguese structure after se for a future possibility.

Tiveres is the 2nd person singular, so it goes with tu.

The sentence is addressing someone informally:

• Se tiveres... = If you have... (speaking to you, informal singular)

If it were with você, it would be:

• Se tiver um cupão...

So this sentence is clearly in the tu form, which is very common in Portugal.

Dá para is a very common expression meaning something like:

• it is possible to
• you can
• it works for
• it’s enough to

In this sentence:

• dá para comprar esta caneta mais barata

means:

• it’s possible to buy this pen more cheaply
• or more naturally, you can buy this pen more cheaply

It is an impersonal structure. The subject is not a person. Portuguese often uses dá para + infinitive where English might simply say you can.

Other examples:

• Dá para entrar por aqui? = Can you get in this way?
• Não dá para ver nada. = You can’t see anything / It’s impossible to see anything.
• Dá para fazer hoje. = It’s possible to do it today.

The accent in dá shows both pronunciation and meaning.

• dá = he/she/it gives or part of expressions like dá para
• da = contraction of de + a = of the / from the / to the, depending on context

So they are different words:

• dá para comprar = it is possible to buy
• a tampa da caneta = the pen’s cap

The accent helps distinguish them.

Portuguese often uses mais barato / mais barata where English might use:

• more cheaply
• for less
• at a lower price

So:

• comprar esta caneta mais barata

literally looks like buy this pen cheaper, but the natural meaning is:

• buy this pen more cheaply
• buy this pen for less

This is a normal and natural Portuguese way to express price reduction.

You could also hear things like:

• comprar mais barato
• sair mais barato
• ficar mais barato

all related to lower cost.

Because barata agrees with caneta, and caneta is a feminine singular noun.

• uma caneta barata = a cheap pen
• um livro barato = a cheap book

Here, even though the sentence contains comprar, the word barata still relates to caneta:

• esta caneta mais barata = this pen cheaper / at a cheaper price

So the adjective takes the feminine singular form:

• barata

In practice, it expresses the price of the pen in that buying situation.

Grammatically, barata agrees with caneta, so it is attached to the noun. But the meaning is not really that the pen becomes a different kind of pen; it means the pen can be bought at a lower price.

So the idea is:

• buy this pen more cheaply
• get this pen for less

Portuguese often uses this noun + adjective pattern where English might prefer an adverbial expression.

Yes, absolutely.

That version is also natural:

• Se tiveres um cupão, podes comprar esta caneta mais barata.

This means almost the same thing as the original.

The difference is mainly in style:

• dá para comprar... = it’s possible to buy...
• podes comprar... = you can buy...

The version with dá para sounds a bit more impersonal and general. The version with podes addresses the listener more directly.

In European Portuguese, cupão means coupon or voucher, especially for discounts.

Its spelling follows European Portuguese usage:

• cupão

In Brazilian Portuguese, you are more likely to see:

• cupom

So this is a good example of a small Portugal/Brazil vocabulary and spelling difference.

In European Portuguese, cupão is pronounced roughly like:

• koo-POWN

The stress is on the last syllable because of -ão.

A few helpful points:

• cu- sounds like koo
• -pão has the nasal ão sound, common in Portuguese
• the final -ão is not like English own exactly, but ow̃ is a useful approximation

If you already know words like não, pão, or coração, the ending is the same type of nasal sound.

Esta means this and refers to something close to the speaker, at least in the more traditional three-way system:

• esta = this (near me)
• essa = that (near you)
• aquela = that over there (far from both)

So:

• esta caneta = this pen

In real spoken Portuguese, especially casually, speakers do not always maintain the distinction perfectly, but esta is the standard choice for this pen.

Because caneta is feminine singular, the demonstrative is also feminine singular:

• esta caneta
• not este caneta

Yes. In natural English, that can be a very good translation.

Portuguese ter often corresponds to English:

• have
• have got

So:

• Se tiveres um cupão... can be translated as:
• If you have a coupon...
• If you’ve got a coupon...

Both are fine in English. The Portuguese grammar is different, but the meaning is the same.

Yes, it is natural and idiomatic in European Portuguese.

A native speaker would easily understand it, and the structure is very typical:

• Se + future subjunctive
• dá para + infinitive
• mais barata for a lower price

Very similar natural alternatives would be:

• Se tiveres um cupão, podes comprar esta caneta mais barata.
• Se tiveres um cupão, esta caneta fica mais barata.
• Com um cupão, dá para comprar esta caneta mais barata.

So the original sentence sounds normal and useful for everyday language.