Se raspares a panela com força, vais estragá-la.

Because Portuguese normally uses the future subjunctive after se when talking about a possible future condition.

So:

• Se raspares... = If you scrape...
• Se fizeres... = If you do...
• Se puderes... = If you can...

This is very common in Portuguese and is something English speakers often have to get used to, because English does not have a special tense here.

It comes from the verb raspar.

Here it is in the future subjunctive:

• eu raspar
• tu raspares
• ele/ela/você raspar
• nós rasparmos
• eles/elas/vocês rasparem

In this sentence, raspares matches an implied tu:
Se (tu) raspares...

A useful detail: for many verbs, the future subjunctive looks the same as the personal infinitive.

Because Portuguese often drops subject pronouns when the verb ending already shows who the subject is.

Here, vais clearly tells you the subject is tu:

• (tu) vais
• (tu) raspares

So the full sentence could be:

Se tu raspares a panela com força, tu vais estragá-la.

But that sounds less natural than leaving tu out.

In standard Portuguese, for a future possibility like this, Se raspares... is the normal choice.

So:

• Se raspares a panela... = standard and expected here

Using Se raspas... would not be the normal standard form for this meaning.

A good rule to remember is:

• se + future possibility → often future subjunctive
• se + past hypothetical → often imperfect subjunctive
  Example: Se raspasses..., estragavas...

Com força literally means with force, but in natural English it often means:

• hard
• forcefully
• roughly
• vigorously

So here it means scraping the pan in a strong, harsh way.

Portuguese often uses expressions like com força where English might use a single adverb.

Because ir + infinitive is a very common way to talk about the future in everyday Portuguese.

So:

• vais estragá-la = common, natural, conversational
• estragá-la-ás = grammatically possible, but much more formal and much less common in everyday speech

English does something similar with going to.

Because in this kind of neutral affirmative sentence, Portuguese commonly puts the object pronoun after the verb.

Here the pronoun refers to a panela, so instead of repeating the noun, Portuguese uses -la:

• vais estragar a panela
• vais estragá-la

Both are correct. The second is more elegant because it avoids repeating a panela.

In this structure with ir + infinitive, attaching the pronoun to the infinitive is very normal:

• vou fazê-lo
• vais comprá-lo
• vamos vê-la

This is an important spelling pattern.

The base verb is estragar and the direct object pronoun is a.

When a verb ending in -r, -s, or -z is followed by o / a / os / as, two things happen:

1. the final -r / -s / -z drops
2. the pronoun changes to lo / la / los / las

So:

• estragar + a → estragá-la
• fazer + o → fazê-lo
• pôr + a → pô-la

The accent is added to show the correct stress after the final -r disappears.

It refers to a panela.

Because panela is:

• feminine
• singular

the pronoun must also be:

• feminine singular → a, which becomes -la after a verb ending in -r

If the noun were masculine, you would get -lo instead.

Because it is talking about a specific pan, not just pans in general.

Portuguese uses definite articles very naturally with specific nouns, and here a panela simply means the pan.

So this is not unusual at all. In fact, English would normally also use the in this sentence.

Yes, absolutely.

Both are correct:

• Se raspares a panela com força, vais estragar a panela.
• Se raspares a panela com força, vais estragá-la.

But the second is usually better style because it avoids repeating a panela.

Portuguese, like English, often prefers a pronoun when the noun has just been mentioned.

Yes, it fits European Portuguese very well.

A few features that are especially useful for a learner of Portuguese from Portugal are:

• use of tu-type verb forms: raspares, vais
• very natural use of the future subjunctive after se
• clitic pronoun attachment in estragá-la

So this is a good model sentence for European Portuguese grammar and style.