Se cortares o tomate às rodelas finas, dá para pô-lo na sandes.

Because after se meaning if, Portuguese often uses the future subjunctive when talking about a real possibility in the future.

So:

• Se cortares o tomate... = If you slice the tomato...
• not se cortas..., which would sound wrong in this context in standard Portuguese.

For cortar, the future subjunctive forms are:

• se eu cortar
• se tu cortares
• se ele/ela cortar
• se nós cortarmos
• se vós cortardes
• se eles/elas cortarem

A useful pattern to remember is:

• Se + future subjunctive, then the result clause follows.

Example:

• Se chegares cedo, jantamos juntos.
  If you arrive early, we’ll have dinner together.

In this sentence, it is functioning as the future subjunctive.

But this is confusing for learners because with many verbs, the future subjunctive and the personal infinitive look exactly the same.

For cortar:

• future subjunctive (tu): cortares
• personal infinitive (tu): cortares

They look identical, but the structure tells you which one it is.

Here, because it comes after se with the meaning if, it is understood as future subjunctive:

• Se cortares o tomate...

Às rodelas means into round slices or in slices.

So:

• cortar o tomate às rodelas = to slice the tomato into rounds

Then finas means thin, agreeing with rodelas:

• rodelas finas = thin slices

So the whole phrase means:

• cut/slice the tomato into thin rounds

This is a very natural Portuguese food expression. Similar expressions are:

• às fatias = in slices
• aos cubos = into cubes
• às tiras = into strips

Because cortar às rodelas is a fixed, idiomatic way of saying cut into slices/rounds.

The structure a + as = às is part of the expression.

So:

• cortar às rodelas
• cortar às fatias
• cortar aos cubos

You do not normally translate this word-for-word. It is just the standard Portuguese pattern for describing the shape something is cut into.

Dá para is a very common expression meaning something like:

• it works to...
• it’s possible to...
• you can...
• it’s suitable for...

In this sentence:

• dá para pô-lo na sandes
  = you can put it in the sandwich
  = it works in a sandwich

It does not literally mean gives for in natural English, even though that is the literal breakdown.

Other examples:

• Dá para ver daqui. = You can see it from here.
• Dá para fazer hoje. = It’s possible to do it today.
• Este pão dá para tostas. = This bread works for toast.

Because -lo is the object pronoun o attached to the infinitive pôr.

Here, o means it, referring to o tomate.

So:

• pôr = to put
• o = it
• pô-lo = to put it

When certain Portuguese infinitives ending in -r, -s, or -z take an attached pronoun like o / a / os / as, the final consonant drops and the pronoun changes:

• pôr + o → pô-lo
• fazer + o → fazê-lo
• comer + a → comê-la

So pô-lo is the normal contracted form.

Because in Portuguese, when the direct object pronouns o, a, os, as are attached to a verb form ending in -r, -s, or -z, they change to:

• lo
• la
• los
• las

And the final consonant of the verb drops.

Examples:

• ver + o → vê-lo
• fazer + os → fazê-los
• traz + a → trá-la

So:

• pôr + o → pô-lo

This is a standard grammar rule, not something unique to this sentence.

Because the verb is pôr, which already has a circumflex accent: ô.

When the pronoun is attached, the infinitive loses the final -r, but the stressed vowel remains:

• pôr → pô-lo

The accent helps preserve both pronunciation and spelling.

Compare:

• pôr → pô-lo
• fazer → fazê-lo
• comer → comê-lo

Na sandes means in the sandwich.

It is made from:

• em + a = na

So:

• na sandes = in the sandwich

As for gender, in European Portuguese sandes is a feminine noun:

• a sandes
• uma sandes
• na sandes

This is simply something you need to learn with the word.

Yes, sandes is very characteristic of European Portuguese.

In Portugal, sandes is a common everyday word for sandwich.

You may also hear:

• sanduíche — more common in Brazilian Portuguese
• sandes mista — a ham-and-cheese toasted sandwich in Portugal

So if you are learning Portuguese from Portugal, sandes is the natural word to know.

Portuguese often uses the singular where English might use either singular or plural, depending on the situation.

Here, o tomate can mean:

• the tomato
• or more generally tomato as an ingredient

So the sentence is talking about tomato as something you are preparing for the sandwich, not necessarily emphasizing quantity.

A very similar English sentence would be:

• If you slice the tomato thinly, you can put it in the sandwich.

That sounds natural too.

Both are possible, but they mean slightly different things.

• na sandes = in the sandwich
  This sounds like a specific sandwich already understood from context.
• numa sandes = in a sandwich
  This is more indefinite and general.

In your sentence, na sandes suggests a particular sandwich being prepared.

Yes. In everyday Portuguese, especially in speech, meter is very common and often means the same as pôr in this context.

So you could hear:

• dá para metê-lo na sandes

That said:

• pôr is very common and perfectly natural
• meter can sound slightly more colloquial in some contexts

Both are useful to know.

Yes, it fits European Portuguese very well.

European Portuguese strongly prefers attaching object pronouns to the verb in many neutral affirmative contexts, especially with infinitives:

• pô-lo
• fazê-lo
• comê-lo

So dá para pô-lo na sandes sounds very natural in Portugal.

In Brazilian Portuguese, people often prefer different structures in everyday speech, such as:

• dá para colocar ele na sanduíche
  or more naturally with a different wording

But for European Portuguese, pô-lo is the kind of structure you should definitely get used to reading and hearing.

Not usually. It is better to learn it as a chunk.

Literal translation:

• gives for

Natural translation:

• you can
• it works
• it’s possible
• it’s good enough to

In this sentence, the most natural English translations are:

• If you slice the tomato thinly, you can put it in the sandwich.
• If you cut the tomato into thin slices, it’ll work in the sandwich.

So yes, understand the literal pieces if you want, but do not translate it word-for-word when speaking English.

A few natural English versions are:

• If you slice the tomato thinly, you can put it in the sandwich.
• If you cut the tomato into thin slices, you can put it in the sandwich.
• If you slice the tomato into thin rounds, it’ll work in the sandwich.

The second one is often the clearest translation for learners because it matches the Portuguese structure well.