Eu leio uma parte do livro antes de dormir.

I read a part of the book before sleeping.

Breakdown of Eu leio uma parte do livro antes de dormir.

• eu: I
• de: of
• ler: to read
• o livro: the book
• uma: a
• antes: before
• dormir: to sleep
• a parte: the part

Questions & Answers about Eu leio uma parte do livro antes de dormir.

Why do we use eu here? Can I just say Leio uma parte do livro antes de dormir?

In European Portuguese you can drop the subject pronoun because the verb ending already shows who is doing the action.

• Eu leio uma parte do livro antes de dormir. = I read…
• Leio uma parte do livro antes de dormir. = I read… (still clearly “I”)

We usually omit eu in neutral sentences.
We keep eu for emphasis or contrast, for example:

• Eu leio uma parte do livro, tu vês televisão.
  I read part of the book, you watch TV.

So your sentence is correct both with and without eu.

Why is it leio and not something like lero? How is ler conjugated?

Ler (to read) is irregular in the present tense. The full present indicative:

• eu leio – I read
• tu lês – you read (informal singular)
• ele / ela lê – he / she reads
• nós lemos – we read
• vós ledes – you read (very rare / old‑fashioned)
• eles / elas leem – they read

So leio is just the irregular 1st person singular form. There is no form *lero in standard Portuguese.

Does eu leio mean “I read” (in general) or “I am reading” (right now)?

In Portuguese, the present simple often covers both meanings, depending on context:

• Habit / routine:
  Eu leio uma parte do livro antes de dormir.
  I read part of the book before going to sleep (every night / usually).

• Right now / at the moment:
  Eu leio o livro agora.
  I am reading the book now.

If you really want to stress the “right now” idea in European Portuguese, you normally use:

• Estou a ler o livro. – I am reading the book.

But your sentence, with a routine context antes de dormir, is naturally understood as a habit.

Why is it uma parte and not um parte?

Because parte is a feminine noun in Portuguese.

• a parte / uma parte – the part / a part
• o livro / um livro – the book / a book (masculine)

The article and any adjectives must match the gender of the noun they refer to:

• uma parte pequena – a small part (feminine)
• um livro pequeno – a small book (masculine)

So we say uma parte do livro, not *um parte do livro.

What exactly is do in uma parte do livro? Why not de o livro?

Do is a compulsory contraction of the preposition de + the masculine singular article o:

• de + o = do
• de + os = dos
• de + a = da
• de + as = das

So:

• uma parte do livro = a part of the book
  (uma parte de o livro is grammatical only if you contract it to do; you cannot leave it separated.)

In this sentence, we’re talking about a specific book, so we use the definite article:

• uma parte do livro – a part of the (known) book
• uma parte de um livro – a part of a (non‑specific) book

Could I say Eu leio uma parte de um livro antes de dormir? What’s the difference from do livro?

Yes, that’s grammatically correct, but the meaning changes slightly:

• uma parte do livro
  A part of the book – a specific book that both speaker and listener know about.

• uma parte de um livro
  A part of a book – not a specific book already known; just “some book”.

You might use de um livro if the book isn’t important or hasn’t been mentioned:

• Antes de dormir, leio sempre uma parte de um livro qualquer.
  Before sleeping I always read a part of some book or other.

With do livro, the book is identified or already in the conversation.

Can I drop uma and just say Eu leio parte do livro antes de dormir?

Yes, you can:

• Eu leio uma parte do livro…
• Eu leio parte do livro…

Both are correct. Uma parte is a bit more explicit, like “a (certain) part” or “some portion”.
Without uma, parte do livro feels a little more general or abstract, like “part of the book”, but in everyday speech the difference is subtle and both sound natural.

Why is it antes de dormir and not just antes dormir?

In Portuguese, antes normally needs the preposition de before a verb:

• antes de + infinitive
  antes de dormir – before sleeping
  antes de comer – before eating
  antes de sair – before leaving

*antes dormir is not correct.

So the structure is:

• antes de + [verb in infinitive]

Could I say antes de eu dormir instead of antes de dormir? What’s the difference?

Yes:

• antes de dormir – before sleeping (subject is understood from context, usually “I” here)
• antes de eu dormir – before I sleep

Antes de dormir is more neutral and very common when the subject is obvious.

Antes de eu dormir:

• is more explicit about the subject being eu,
• can sound a bit more formal or emphatic,
• is useful if there could be ambiguity about who sleeps.

In your sentence, antes de dormir is the most natural version.

What’s the pronunciation of the whole sentence in European Portuguese?

A simple, approximate guide:

• Eu – like “eh-oo” blended, something like “eh-oo” → [ew]
• leio – LAY‑oo → [ˈlej.u]
• uma – OO‑mɐ (final a reduced, like an unstressed “uh”) → [ˈu.mɐ]
• parte – PAR‑tɨ (final e also reduced) → [ˈpaɾ.tɨ]
• do – doo but short → [du]
• livro – LEE‑vroo → [ˈli.vɾu]
• antes – UN‑tɨsh (final s = “sh” sound in Portugal) → [ˈɐ̃.tɨʃ]
• de – very reduced, like a quick “dɨ” → [dɨ]
• dormir – door‑MEER (Portuguese r is tapped) → [duɾˈmiɾ]

Joined together, roughly:

• Eu leio uma parte do livro antes de dormir.
  ≈ [ew ˈlej.u ˈu.mɐ ˈpaɾ.tɨ du ˈli.vɾu ˈɐ̃.tɨʃ dɨ duɾˈmiɾ]

In natural speech, some vowels get very short and the words link smoothly.

How would I say “I am reading a part of the book before I sleep” in European Portuguese using a continuous form?

European Portuguese normally uses estar a + infinitive for the continuous:

• Eu estou a ler uma parte do livro antes de dormir.

This is the closest to English “I am reading…”.

In everyday speech people often just say:

• Estou a ler uma parte do livro antes de dormir.
  (dropping eu, as usual.)

Could I move antes de dormir to the beginning: Antes de dormir, eu leio uma parte do livro?

Yes, that word order is perfectly natural:

• Eu leio uma parte do livro antes de dormir.
• Antes de dormir, eu leio uma parte do livro.

Both mean the same thing.
Putting Antes de dormir first simply emphasizes the time frame a bit more (“Before I sleep, I read…”).

If I want to say “I read it before going to sleep,” replacing o livro with “it”, how would that be in European Portuguese?

A natural option is to use the direct object pronoun o (for a masculine singular noun like o livro):

• Eu leio-o antes de dormir.
  (In careful writing; in speech the hyphen is often not pronounced clearly.)

In European Portuguese, object pronouns usually attach to the verb with a hyphen (especially in formal writing):

• leio-o – I read it
• vejo-o – I see it
• compro-o – I buy it

In everyday spoken Portuguese, many speakers rearrange or avoid these pronouns, but leio-o is the standard form you’ll see in grammars and formal texts.