às vezes/à noite/à tarde

Crase in Fixed Expressions

Level 3

The expressions às vezes (sometimes), à noite (at night), and à tarde (in the afternoon) always use a grave accent (crase) because they are fixed feminine adverbial phrases.

How It Works

These expressions function as locuções adverbiais de tempo (adverbial phrases of time). They tell us when an action happens.

1. Why the accent?
The crase is mandatory in these fixed phrases because the base noun (vezes, noite, tarde) is feminine. It distinguishes the adverb from the noun itself. For example:

  • À noite (Adverb): Trabalho à noite. (I work at night.)
  • A noite (Noun): A noite está fria. (The night is cold.)

2. The 'Morning' Exception
Be careful: while we use à tarde and à noite, the phrase for 'in the morning' is de manhã. We do not use the crase for morning in this context.

3. Pronunciation and Regional Differences
In Brazilian Portuguese, the pronunciation of a and à is usually identical, making the accent a written convention. However, in European Portuguese, they are phonetically distinct: a is a closed vowel [ɐ], while à is an open vowel [a]. This makes the accent phonetically relevant for speakers in Portugal and Africa.

4. Usage and Register
These are standard in all forms of Portuguese. In casual speech, you may also hear de noite or de tarde. However, às vezes remains the most common way to say 'sometimes' across all registers.

Examples (4)

  1. Às vezes, eu prefiro caminhar no parque.

    Sometimes, I prefer to walk in the park.

    Word by Word: At the times, I prefer to walk in the park.

    'Às vezes' is a fixed expression meaning 'sometimes'. It always takes the plural crase.

  2. Nós sempre estudamos à noite.

    We always study at night.

    Word by Word: We always study at the night.

    'À noite' indicates the period of time when the studying happens.

  3. O sol é muito forte à tarde.

    The sun is very strong in the afternoon.

    Word by Word: The sun is very strong at the afternoon.

    'À tarde' is the standard way to express 'in the afternoon' using the crase.

  4. Eu te ligo amanhã à tarde.

    I will call you tomorrow afternoon.

    Word by Word: I you call tomorrow at the afternoon.

    Even when combined with other time words like 'amanhã', the crase remains mandatory.

Common Mistakes

  • Using crase when the word is the subject of the sentence.

    À noite foi muito longa.
    A noite foi muito longa.

    If 'night' is the subject (The night was long), you only use the article 'A'. Use 'À' only when it means 'at night'.

  • Applying crase to masculine time expressions.

    Eu saio à dia.
    Eu saio ao dia.

    Crase only occurs with feminine nouns. For masculine nouns like 'dia', use the contraction 'ao' (a + o).

  • Overgeneralizing the rule to 'morning'.

    Eu estudo à manhã.
    Eu estudo de manhã.

    While we use à noite and à tarde, the expression for 'in the morning' is always 'de manhã'. Using 'à manhã' is a common error for learners.

How It Connects

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às vezes/à noite/à tardeLevel 3Crase in Fixed Expressions

Learn This First

To understand 'crase' in fixed expressions like 'às vezes', you first need to understand how the preposition 'a' and the feminine article 'a' merge into a single sound and symbol (à). You also need to recognize that these specific expressions use feminine nouns, which is why the feminine contraction is required.

Words in This Pattern

às vezesà noiteà