O ralador ficou na gaveta, e cada pessoa comeu uma fatia.

Because na is the contraction of em + a.

• em = in
• a = the (feminine singular)

So:

• em a gaveta → na gaveta

This kind of contraction is very common in Portuguese:

• em + o = no
• em + a = na
• em + os = nos
• em + as = nas

Since gaveta is feminine, na gaveta is the correct form.

In Portuguese, nouns have grammatical gender. Ralador is a masculine noun, so it takes o in the singular:

• o ralador = the grater

You usually have to learn the gender with the noun. A helpful clue here is that many nouns ending in -dor are masculine:

• o ralador
• o computador
• o elevador

But this is a pattern, not an absolute rule for every noun in the language.

Yes. Ficou is the pretérito perfeito (simple past) of ficar, for ele/ela/você.

Here, ficar means something like:

• stayed
• remained
• was left

So O ralador ficou na gaveta suggests that the grater remained in the drawer or was left there.

That is different from other common uses of ficar, such as:

• ficar cansado = to become tired
• ficar em casa = to stay at home

So ficar is a very flexible verb, and the exact meaning depends on context.

These forms are related to different ideas.

• ficou = stayed / ended up / remained
• estava = was / was located / was in a state

Compare:

• O ralador ficou na gaveta
  The grater stayed in the drawer / was left in the drawer.

• O ralador estava na gaveta
  The grater was in the drawer.

So ficou often suggests a result or a change leading to that situation, while estava simply describes the situation.

In Portuguese, a comma before e is sometimes used when two full clauses are being joined, especially if they have different subjects or if the writer wants a slight pause.

Here the two clauses are:

• O ralador ficou na gaveta
• cada pessoa comeu uma fatia

They have different subjects:

• o ralador
• cada pessoa

So the comma is acceptable. You may also see the sentence written without it:

• O ralador ficou na gaveta e cada pessoa comeu uma fatia.

That would also be normal.

Cada pessoa means each person, so it focuses on people one by one.

• cada pessoa = each person
• todas as pessoas = all the people / every person collectively

This matters because cada is grammatically singular:

• Cada pessoa comeu...
  literally Each person ate...

If you said todas as pessoas, the verb would normally be plural:

• Todas as pessoas comeram uma fatia.

So cada pessoa emphasizes individual distribution.

Because cada takes a singular noun and normally requires a singular verb.

So:

• cada pessoa comeu
• not cada pessoa comeram

This is the same idea as in English:

• Each person ate
• not Each person ate with a plural verb

Other examples:

• Cada aluno recebeu um livro.
• Cada casa tem uma porta.

Even though cada pessoa refers to more than one person in real life, the grammar is singular.

Fatia usually means a slice.

It is used for things that can be cut into slices, such as:

• uma fatia de pão = a slice of bread
• uma fatia de queijo = a slice of cheese
• uma fatia de bolo = a slice of cake

So cada pessoa comeu uma fatia means each person ate one slice.

A learner may compare it with pedaço:

• fatia = slice
• pedaço = piece

A fatia is usually more specifically shaped like a slice, while pedaço is more general.

Because the sentence is talking about what each individual person ate.

• cada pessoa comeu uma fatia = each person ate one slice

So the logic is:

• one person → one slice
• another person → one slice
• another person → one slice

That is why uma fatia stays singular. This is very common after cada:

• Cada aluno trouxe um livro.
• Cada criança ganhou um presente.

Normally no. In this sentence, uma is needed.

• comeu uma fatia = ate a slice

Without the article, comeu fatia, it sounds incomplete or unnatural in standard Portuguese.

Portuguese often uses an article or determiner where English might be a bit more flexible. Here, uma clearly introduces a countable singular noun.

Comeu is the pretérito perfeito do indicativo of comer, for ele/ela/você.

Conjugation:

• eu comi
• tu comeste
• ele/ela/você comeu
• nós comemos
• vós comestes
• eles/elas/vocês comeram

In this sentence, comeu is singular because the subject is cada pessoa.

This tense is used for a completed action in the past.

This is the most neutral and natural word order in Portuguese:

• subject + verb + place

So:

• O ralador = subject
• ficou = verb
• na gaveta = location

Portuguese can change word order for emphasis, but the sentence as written is the standard, straightforward version.

For example, Na gaveta ficou o ralador is possible, but it sounds more marked or literary, because it emphasizes the location first.

A few useful pronunciation notes for Portugal Portuguese:

• o at the end of a word often sounds like u
  So ralador ends with a sound close to -dor, and o by itself often sounds like u in connected speech.

• e in unstressed syllables is often reduced
  So words like gaveta and pessoa may sound more reduced than an English speaker expects.

• comeu is said as one word, not like two separate syllables in English style
  The ending -eu has a diphthong sound.

A rough learner-friendly approximation might be:

• O ralador → u ra-la-DOR
• gaveta → ga-VE-ta (with reduced unstressed vowels)
• comeu → kuh-MEU

These are only approximations, but they reflect common European Portuguese pronunciation tendencies.

Yes. Pessoa is grammatically singular here because it is part of the expression cada pessoa.

• pessoa = person
• pessoas = people / persons

Since cada normally goes with a singular noun, you say:

• cada pessoa
• not cada pessoas

This is one of the most important patterns to remember with cada.

Yes, that would be grammatical, but it changes the structure and slightly changes the emphasis.

Compare:

• cada pessoa comeu uma fatia
  Focuses on each individual person.

• todas as pessoas comeram uma fatia
  Focuses on the group as a whole.

Both can often be translated naturally into English, but cada pessoa sounds more distributive: one slice per person, considered individually.