Usei a pá para tirar a raiz depois da colheita.

Usei is the 1st person singular of usar in the pretérito perfeito (the simple past / completed past).

So usei = I used.

It tells you that the speaker is talking about one completed action in the past. In this sentence, the action of using the shovel is seen as finished.

Portuguese often omits the subject pronoun when the verb ending already makes the subject clear.

• usei already clearly means I used
• so eu usei is possible, but not necessary

You would add eu mainly for:

• emphasis
• contrast
• clarity

For example:

• Eu usei a pá, não ele. = I used the shovel, not him.

Pá means a shovel or spade, depending on context.

In this sentence, it is a tool used for digging or removing something from the ground. A native speaker may imagine either:

• a shovel
• a spade

The exact English word depends on the situation, but pá is the normal Portuguese word for that kind of digging tool.

Also, notice the accent:

• pá = shovel / spade

This is different from the very informal spoken word pá used in Portugal as a filler word like mate or man in conversation. Here it is clearly the noun meaning the tool.

A means the, while uma means a/an.

So:

• a pá = the shovel
• a raiz = the root
• a colheita = the harvest

Portuguese often uses the definite article when the thing is:

• already known in the context
• specific
• understood from the situation

So this sentence sounds like the speaker has a particular shovel, root, and harvest in mind.

If you said:

• Usei uma pá para tirar uma raiz...

that would sound more like:

• I used a shovel to remove a root...

which is also grammatically possible, but slightly different in meaning.

Para + infinitive often expresses purpose.

So:

• para tirar = to remove, to take out, in order to remove

It answers the question what for?

• Usei a pá para tirar a raiz
  = I used the shovel to remove the root

This structure is very common in Portuguese:

• Usei a faca para cortar o pão.
• Abri a janela para arejar o quarto.

Tirar is a very common verb with a broad meaning. Depending on context, it can mean:

• to take off
• to remove
• to take out
• to pull out
• to extract

In this sentence, tirar a raiz means something like:

• remove the root
• pull out the root
• take the root out

So the exact English translation depends on context, but the idea is removing the root from where it was.

Yes, sometimes it could, but the meaning would be a bit different.

• tirar a raiz = remove / take out the root
• arrancar a raiz = pull out / rip out / uproot the root

Arrancar often sounds stronger and more forceful.
Tirar is broader and more neutral.

So tirar works well if the focus is simply that the root was removed, while arrancar suggests more of a forceful pulling-up action.

Because de + a contracts to da in Portuguese.

So:

• de a colheita → da colheita

This kind of contraction is very common and usually required in normal Portuguese.

Other common contractions:

• de + o = do
• em + a = na
• em + o = no
• a + a = à

So:

• depois da colheita = after the harvest

It is a time expression.

• depois de = after
• da colheita = the harvest

Together:

• depois da colheita = after the harvest

It tells you when the action happened.

In the sentence, it most naturally means that the speaker used the shovel to remove the root after the harvest had taken place.

Yes. Portuguese word order is fairly flexible, especially with time expressions.

The original sentence:

• Usei a pá para tirar a raiz depois da colheita.

You could also say:

• Depois da colheita, usei a pá para tirar a raiz.

Both are natural. The second version puts more focus on the timing.

In the original, placing it at the end is very normal and neutral.

A rough European Portuguese pronunciation would be:

Usei a pá para tirar a raiz depois da colheita.
≈ oo-ZAY ee PAH puh-ruh tee-RAR uh ruh-EESH duh-POYSH dah koo-LYAY-tuh

A few useful points:

• usei sounds roughly like oo-ZAY
• pá has a clear stressed ah
• raiz in European Portuguese ends with a sound like sh: ruh-EESH
• colheita has the lh sound, like the lli in million for many English speakers: koo-LYAY-tuh
• depois in Portugal often sounds like duh-POYSH

This is only an approximation, but it helps highlight the main sounds.

It works in both European Portuguese and Brazilian Portuguese.

The grammar and vocabulary are standard and natural in both varieties:

• Usei
• a pá
• para tirar a raiz
• depois da colheita

What changes most is the pronunciation, not the basic structure.

For example:

• European Portuguese pronunciation is generally more reduced
• Brazilian Portuguese pronunciation is usually more open and clearer vowel-by-vowel

But as a sentence, it is correct and understandable in both.