Au singulier, ce nom est masculin, mais au pluriel il change un peu à l’écrit.

Au singulier means in the singular or when the word is singular.

Here, au is the contraction of à + le:

• à = in / at / to
• le = the
• au = à le

So literally, au singulier is something like in the singular.

This is a very common grammar expression, just like:

• au pluriel = in the plural
• au féminin = in the feminine
• au masculin = in the masculine

Because nom begins with a consonant sound: n.

French uses:

• ce before most masculine singular nouns
• cet before masculine singular nouns that begin with a vowel or mute h

So:

• ce nom = correct
• cet arbre = correct
• cet homme = correct

Since nom starts with n, you use ce.

In everyday French, nom often means name, but in grammar explanations it can also mean noun.

So in this sentence, ce nom means this noun or this word being discussed.

That is very common in dictionaries, grammar notes, and language-learning materials.

Here, masculin refers to grammatical gender, not biological sex.

French nouns are grammatically:

• masculin = masculine
• féminin = feminine

So ce nom est masculin means the noun takes masculine articles and adjectives, for example:

• le
• un
• masculine adjective forms

It does not mean the object itself is male. It is just a grammar category.

Because masculin is the French word, not the English one.

The whole sentence is in French, so the grammar label is given in French:

• masculin = masculine
• féminin = feminine
• singulier = singular
• pluriel = plural

French grammar notes usually use the French terms themselves.

Mais means but.

It introduces a contrast:

• in the singular, the noun is masculine
• but in the plural, something changes a little in writing

So the sentence is contrasting two facts about the noun:

1. its gender in the singular
2. its written form in the plural

Au pluriel means in the plural or when the word is plural.

Just like au singulier, it is a fixed grammar expression.

So:

• Au singulier = in the singular form
• Au pluriel = in the plural form

It does not necessarily mean the gender changes. It means the form of the word changes when you use the plural.

Il refers back to ce nom.

Since nom is a masculine singular noun, the pronoun used to refer to it is il.

So:

• ce nom est masculin
• mais au pluriel il change...

In English, we might repeat the noun or say it. French does the same here with il = it.

Change un peu means changes a little.

So the sentence is saying that when the noun becomes plural, it does not stay exactly the same in writing. Its spelling changes slightly.

This often happens with irregular plurals or words that do not just add a simple -s.

À l’écrit means in writing or in the written form.

It contrasts with:

• à l’oral = in speech / when spoken

So il change un peu à l’écrit means:

• the spelling changes a little
• this is something you notice in the written form

This wording is natural in grammar explanations. It suggests that the difference may be mainly visual, not necessarily a big pronunciation change.

Because French often leaves out an understood word in grammar expressions.

For example:

• au singulier
• au pluriel

These really mean something like:

• à la forme singulière
• à la forme plurielle

But French usually uses the shorter version. It is just a standard way to talk about grammar.

English does something similar when we say:

• in the singular
• in the plural

Both are in the present tense:

• est = is
• change = changes

French uses the present tense very often to state general facts, definitions, and grammar rules.

So here the present is being used to describe a general truth about the noun:

• it is masculine in the singular
• it changes a little in writing in the plural

Often, yes—that is the implication.

When a grammar note says something changes à l’écrit, it usually focuses on the spelling, not the pronunciation.

That does not absolutely guarantee the pronunciation stays identical, but it strongly suggests:

• the written form changes
• the spoken form may change little or not at all

This is especially common in French, where plural spelling changes are sometimes visible in writing but not clearly heard in speech.