Se o cursor ficar preso, desliga o rato e volta a ligá-lo.

Se means if.

So:

• Se o cursor ficar preso = If the cursor gets stuck

It introduces a condition, just like if in English.

A very common pattern in Portuguese is:

• Se + clause, ... = If + clause, ...

For example:

• Se chover, fico em casa. = If it rains, I stay home.
• Se precisares de ajuda, diz. = If you need help, say so.

Ficar often means to become or to end up in a certain state, while estar means to be in that state.

So:

• ficar preso = to get stuck / to become stuck
• estar preso = to be stuck

In this sentence, ficar preso is used because it refers to the moment or situation where the cursor gets stuck.

Compare:

• Se o cursor ficar preso... = If the cursor gets stuck...
• O cursor está preso. = The cursor is stuck.

Here, preso means stuck.

The word preso literally comes from the idea of being caught, held, or trapped, so its meaning changes depending on context.

Examples:

• ficar preso no elevador = to get stuck in the lift
• o cursor ficou preso = the cursor got stuck
• foi preso pela polícia = he was arrested by the police

So yes, preso can also mean arrested, but in this sentence it clearly means stuck.

Portuguese often uses the definite article where English might also use the, especially when referring to a specific thing already understood in context.

Here:

• o cursor = the cursor
• o rato = the mouse

The idea is not just any cursor or any mouse, but the one relevant to the situation: the cursor on your screen and the mouse you are using.

Also, both nouns are masculine singular:

• o cursor
• o rato

That matters later when the pronoun -lo is used, because it refers back to o rato.

Yes. Rato normally means the animal mouse, but in Portuguese from Portugal it is also the standard word for the computer mouse.

So in Portugal:

• rato = mouse (animal)
• rato = computer mouse

This is completely normal, just like English uses mouse for both.

A learner should know that this is standard European Portuguese. In Brazil, mouse is also very common.

Desliga is the tu imperative form, used when speaking directly and informally to one person.

So:

• desliga = turn off (informal singular, you = tu)

Compare:

• desliga → informal singular
• desligue → formal singular / você / polite instruction

This sentence is giving a direct instruction in an informal style.

The same happens with liga in the second part, although there it appears inside ligá-lo.

If the sentence were more formal, it might be:

• Se o cursor ficar preso, desligue o rato e volte a ligá-lo.

Portuguese often leaves out the subject pronoun when it is already clear from the verb form.

So instead of saying:

• tu desliga o rato — which would actually be wrong here

Portuguese simply says:

• desliga o rato

The verb ending already shows who the instruction is for.

This is very common in Portuguese. Subject pronouns like eu, tu, ele, etc. are often omitted unless needed for emphasis or clarity.

Voltar a + infinitive means to do something again or to do something back.

So:

• volta a ligar = turn on again
• volta a tentar = try again
• volta a escrever = write again

In this sentence:

• volta a ligá-lo = turn it back on / switch it on again

This is a very common structure in Portuguese.

This is an important European Portuguese grammar point.

The base verb is:

• ligar = to turn on / to connect / to call, depending on context

The object pronoun is:

• o = it / him (masculine singular)

When o is attached to a verb ending in -r, the -r drops and o changes to -lo.

So:

• ligar + o → ligá-lo

The accent appears to keep the correct stress.

This same pattern happens with other infinitives ending in -r:

• fazer + o → fazê-lo
• ver + o → vê-lo
• pôr + o → pô-lo

So ligá-lo means to turn it on.

-lo refers to o rato.

Because rato is masculine singular, the pronoun is:

• o → when attached after a verb form in this context, it becomes -lo

So:

• desliga o rato = turn off the mouse
• volta a ligá-lo = turn it back on

In other words, -lo = it, specifically the mouse.

In European Portuguese, object pronouns are very often attached to the end of the verb. This is called enclisis.

So you get forms like:

• liga-o = turn it on
• faz-me = do/make for me
• diz-lhe = tell him/her

That is why the sentence has:

• ligá-lo

with a hyphen.

This is especially common in affirmative main clauses in European Portuguese.

Because Portuguese normally uses a clitic object pronoun, not a full separate pronoun like English it.

So the natural form is:

• volta a ligá-lo

Not:

• volta a o ligar — unnatural here
• volta a ligar ele — wrong, because ele means he, not object it

Portuguese object pronouns work differently from English ones. In this sentence, the correct object form is the clitic pronoun attached to the verb.

In form, desliga can look like the he/she present tense or the tu imperative, but here it is understood as an imperative because the sentence is giving an instruction.

So here:

• desliga o rato = turn off the mouse

not

• he/she turns off the mouse

Context tells you it is an instruction.

This is very common in Portuguese: the same form can serve more than one function, and the context makes the meaning clear.

Yes, but the meaning shifts slightly.

• Se o cursor ficar preso = If the cursor gets stuck
• Se o cursor estiver preso = If the cursor is stuck

So:

• ficar focuses on becoming stuck
• estar focuses on the state of already being stuck

In practical terms, both can work in similar situations, but ficar preso is very natural when talking about something going wrong.

Yes. Portuguese offers a few natural alternatives, for example:

• desliga o rato e liga-o novamente
• desliga o rato e torna a ligá-lo
• desliga o rato e volta a ligá-lo

The version in your sentence, volta a ligá-lo, is very natural and common in European Portuguese.

It sounds like a normal instruction: turn it off and then turn it back on.

The sentence has two main parts:

1. Se o cursor ficar preso

   • conditional clause
   • if the cursor gets stuck

2. desliga o rato e volta a ligá-lo

   • instruction
   • turn off the mouse and turn it back on

So the overall pattern is:

• If X happens, do Y.

This is a very useful structure in Portuguese:

• Se tiveres dúvidas, pergunta. = If you have doubts, ask.
• Se não funcionar, reinicia o computador. = If it doesn’t work, restart the computer.
• Se o cursor ficar preso, desliga o rato e volta a ligá-lo. = If the cursor gets stuck, turn off the mouse and turn it back on.