In short

Possessive adjectives (mon, ma, mes…) say whose something is, and demonstrative adjectives (ce, cette, ces) point something out (“this / that”). The key rule: both agree with the noun they precede, not with the English owner - so son livre is “his/her book”, chosen by the gender of livre, not the person.

The rule

Like all French adjectives, these agree with the noun in gender and number. They replace the article: you say mon frère, never le mon frère.

Possessives: mon/ma/mes, ton/ta/tes, son/sa/ses

Each owner has three forms - masculine singular, feminine singular, plural (both genders):

• mon / ma / mes = my: mon vélo, ma voiture, mes amis
• ton / ta / tes = your (informal): ton stylo, ta sœur, tes livres
• son / sa / ses = his / her / its: son père, sa mère, ses enfants

The big trap for English speakers: son/sa/ses do not tell you the owner’s gender. son sac is “his bag” or “her bag” - the form follows sac (masculine), not the person. Context makes the owner clear.

Feminine noun starting with a vowel or silent h. To avoid two vowels clashing, use the masculine form mon/ton/son before a feminine noun that begins with a vowel sound:

• ma amie -> mon amie (my friend, female)
• ta école -> ton école (your school)
• sa histoire -> son histoire (his/her story)

Possessives: notre / votre / leur

The plural owners have just two forms - one for singular, one for plural - and no gender distinction in the singular:

• notre / nos = our: notre maison, nos voisins
• votre / vos = your (formal or plural): votre nom, vos clés
• leur / leurs = their: leur voiture, leurs idées

Note that leur here (their) takes an -s in the plural (leurs), unlike the object pronoun leur (to them), which never does.

Demonstratives: ce / cet / cette / ces

One word covers both English “this” and “that”. The form depends on the noun’s gender, number, and first sound:

• ce - masculine singular before a consonant: ce garçon, ce livre
• cet - masculine singular before a vowel or silent h: cet homme, cet arbre
• cette - feminine singular: cette femme, cette idée
• ces - plural, all genders: ces enfants, ces maisons

cet and cette sound identical but are spelled differently - cet is masculine, cette is feminine.

The ce…-ci / ce…-là contrast

French normally does not distinguish “this” from “that”. When you need to, attach -ci (nearer, “this”) or -là (farther, “that”) to the noun with a hyphen:

• ce livre-ci = this book (here) / ce livre-là = that book (there)
• cette semaine-ci = this week / cette semaine-là = that week
• ces jours-ci = these days

In everyday speech, -là is very common even when there is no real contrast: cette voiture-là often just means “that car”.

Forms & patterns

Possessive adjectives

Reminder: before a feminine noun starting with a vowel sound, use mon / ton / son (mon amie, ton histoire, son école).

Demonstrative adjectives

Examples

Common mistakes

• le mon livre -> mon livre - a possessive replaces the article; never use both.
• ma amie -> mon amie - before a feminine noun starting with a vowel, use mon/ton/son.
• son meaning only “his” -> son = his OR her - the form follows the noun, not the owner.
• ce homme -> cet homme - masculine singular before a vowel sound takes cet, not ce.
• cet femme -> cette femme - cet is masculine only; a feminine noun needs cette.
• ce livre ci -> ce livre-ci - -ci and -là attach to the noun with a hyphen.

Tips

• Choose the form by the French noun, never by the English word: mes parents (plural noun) even though “my” looks singular.
• cet (masc.) and cette (fem.) are pronounced the same - let the noun’s gender pick the spelling.
• Memorize the vowel rule as one set: mon / ton / son / cet all appear before a vowel sound.
• Default to -là if you only remember one: ce truc-là sounds natural in speech even without contrast.
• notre / votre / leur ignore gender in the singular - one form fits masculine and feminine nouns.
• Do not confuse leur (their, adjective, takes -s) with the invariable pronoun leur (to them) from Lesson 23.