Eu sempre tiro a tampa antes de ferver o leite.

Yes. Portuguese often drops subject pronouns because the verb ending already shows the subject. Tiro already means I take off / I remove, so Sempre tiro a tampa antes de ferver o leite is perfectly natural.

Keeping eu is also correct. It can add emphasis, contrast, or simply make the subject extra clear.

Because the simple present in Portuguese is often used for habits and repeated actions, not just things happening right now.

So Eu sempre tiro... means I always take off... / I always remove... as a routine. The word sempre makes that habitual meaning especially clear.

That is the most neutral and common placement in everyday Portuguese: Eu sempre tiro...

You can also hear Eu tiro sempre..., but it sounds more marked or stylistic. For learners, subject + sempre + verb is a very safe pattern.

Yes. Tirar is a very common everyday verb meaning to take, to remove, to take off, depending on context.

So tirar a tampa naturally means remove the lid or take the lid off. Other verbs like remover or retirar are possible, but tirar is the most ordinary and conversational choice.

Portuguese uses definite articles much more often than English.

Here, the speaker means a specific lid and the milk being boiled, so a tampa and o leite sound natural. In English, you often say the lid and the milk too, but Portuguese keeps these articles in many places where English might drop them.

Because Portuguese nouns have grammatical gender.

• tampa is feminine, so it takes a
• leite is masculine, so it takes o

This gender is part of the noun itself. It does not always follow a logical rule from English, so it is best to learn nouns together with their article: a tampa, o leite.

Antes de is the normal expression for before when it is followed by a noun or a verb.

Examples:

• antes do jantar = before dinner
• antes de sair = before leaving

So antes de ferver o leite is the normal structure for before boiling the milk.

Because after the preposition de, Portuguese normally uses the infinitive.

So:

• antes de ferver o leite = before boiling the milk

You would not use the conjugated form directly after de here. That is why ferver is correct, not fervo or ferve.

Usually, yes. This structure often suggests that the subject of both actions is the same.

So Eu sempre tiro a tampa antes de ferver o leite naturally means: I always remove the lid before boiling the milk.

If you want to say before the milk boils, that is a slightly different idea. A common way is:

• antes de o leite ferver
• antes que o leite ferva

They are similar, but not identical.

• antes de ferver o leite = before boiling the milk
  The person in the main clause is understood as the one doing the boiling.

• antes de o leite ferver = before the milk boils
  Now o leite is the subject of ferver.

• antes que o leite ferva = before the milk boils
  This uses a full clause with the subjunctive ferva.

All three are possible, but they focus differently on who/what is doing the boiling.

Yes. In everyday Portuguese, ferver can be:

• intransitive: O leite ferve = the milk boils
• transitive: Eu fervo o leite or ferver o leite = I boil the milk / to boil the milk

So in this sentence, ferver o leite means to boil the milk.

Because a tampa is the direct object of tirar. You are directly removing the lid.

So:

• tirar a tampa = remove the lid

If you want to say where the lid is being removed from, then you add another phrase:

• tirar a tampa da panela = remove the lid from the pot

In real Brazilian Portuguese, yes, you will often hear antes do leite ferver.

In more careful or traditional grammar, many people prefer antes de o leite ferver, because de is introducing the infinitive clause. But the contracted form do is very common in speech and informal writing.