Depois do almoço, eu tomo um copo de suco e como uma banana.

Because do is the normal contraction of de + o in Portuguese.

• depois de = after
• o almoço = lunch
• depois de o almoço becomes depois do almoço

Portuguese uses these contractions very regularly, so de o sounds unnatural here.

Literally, it is something like after the lunch.

In natural English, we usually just say after lunch, but Portuguese often uses the article with meals in expressions like this:

• depois do almoço = after lunch
• antes do jantar = before dinner

So even though English often leaves out the, Portuguese commonly keeps it.

In Brazilian Portuguese, depois do almoço is the natural choice when you mean after lunch as a time reference.

• depois do almoço = after lunch
• depois de almoçar = after eating lunch / after having lunch

Depois de almoço is not the normal standard form in Brazilian Portuguese for this meaning.

So:

• Depois do almoço, eu tomo... = After lunch, I have...
• Depois de almoçar, eu tomo... = After eating lunch, I have...

Both are correct, but they are structured differently.

Yes, you could drop eu.

Portuguese often leaves out subject pronouns when the verb already makes the subject clear:

• eu tomo
• eu como

Because tomo and como clearly show I, many speakers would simply say:

Depois do almoço, tomo um copo de suco e como uma banana.

Including eu is still correct. It may sound slightly more explicit, emphatic, or beginner-friendly.

Yes, tomar can mean to take, but in Brazilian Portuguese it is also very commonly used to mean to drink, especially in everyday speech.

So:

• tomar suco = to drink juice
• tomar café = to have coffee
• tomar água = to drink water

You can also say beber:

• eu bebo suco

That is correct too. But tomar is extremely natural in Brazil for beverages.

Both can work, but they feel a little different in usage.

• tomo um copo de suco = very natural in Brazilian Portuguese
• bebo um copo de suco = also correct, a bit more directly focused on the act of drinking

In many everyday situations, Brazilians use tomar for drinks and beber as a more general verb meaning to drink.

So this sentence sounds very normal as written.

Because um copo de suco is more specific: it means a glass of juice.

Compare:

• eu tomo suco = I drink juice
• eu tomo um suco = I have a juice / a juice drink
• eu tomo um copo de suco = I drink a glass of juice

So the sentence is specifying the quantity or container.

After a container word like copo, Portuguese usually uses de + substance without an article when speaking generally.

• um copo de suco = a glass of juice
• uma xícara de café = a cup of coffee
• uma garrafa de água = a bottle of water

If you say do suco, that usually sounds like you mean a specific juice already known in the conversation:

• um copo do suco que você fez = a glass of the juice you made

So in your sentence, de suco is the normal general form.

Yes. Como is the first-person singular present form of comer:

• eu como = I eat

So the sentence has two present-tense verbs:

• eu tomo = I drink / I have
• (eu) como = I eat

If you know Spanish, be careful not to confuse Portuguese como here with Spanish cómo. In this sentence, it is simply the verb form I eat.

Because Portuguese nouns have grammatical gender.

• copo is masculine → um copo
• banana is feminine → uma banana

The same is true in do almoço:

• almoço is masculine
• so it is o almoço
• and de + o = do

This is about grammatical gender, not biological sex.

Usually it sounds like a habit or routine.

In Portuguese, just like in English, the simple present can describe things someone regularly does:

• Depois do almoço, eu tomo um copo de suco e como uma banana. = After lunch, I drink a glass of juice and eat a banana.

This normally suggests a repeated action, not necessarily something happening at this exact moment.

Because Portuguese does not need to repeat the subject when it stays the same.

So:

• eu tomo um copo de suco e como uma banana

means:

• I drink a glass of juice and eat a banana

Portuguese avoids repeating eu when it is obvious that both verbs have the same subject. You could say eu tomo... e eu como..., but it is less natural unless you want emphasis.

Yes. Portuguese is flexible here.

These are all natural:

• Depois do almoço, eu tomo um copo de suco e como uma banana.
• Eu tomo um copo de suco e como uma banana depois do almoço.
• Depois do almoço, tomo um copo de suco e como uma banana.

The version you were given is very natural because the time expression comes first and sets the scene.

Because Depois do almoço is an introductory time expression.

In English, we often do the same:

• After lunch, I drink a glass of juice and eat a banana.

The comma helps separate the time phrase from the main clause. In short sentences, some punctuation choices can vary, but the comma here is standard and clear.