Lingo Pal

In short

My, your and his/her change with the thing owned: mon/ton/son (masculine), ma/ta/sa (feminine), mes/tes/ses (plural). The owner's gender doesn't matter, so sa sœur is both "his sister" and "her sister". Before a feminine noun starting with a vowel sound, use mon, ton, son: mon amie.

Grammar

Possessive adjectives mon, ma, mes

To say 'my', French uses three words: mon with a masculine singular noun (mon père), ma with a feminine singular noun (ma mère), and mes with any plural noun (mes parents). For 'your' (informal) it is ton, ta, tes, and for 'his' or 'her' it is son, sa, ses.

The word agrees with the thing owned, not with the owner. In English 'his sister' and 'her sister' differ, but in French both are sa sœur. So sa sœur can mean either 'his sister' or 'her sister'; the context tells you.

One special rule: before a feminine noun that starts with a vowel sound, use mon, ton, son for easier pronunciation: mon amie, ton école. English speakers often write ma amie, which is wrong.

mon / ma / mes	my
ton / ta / tes	your (informal)
son / sa / ses	his, her, its

Mon père habite à Lyon.

My father lives in Lyon.

Ma mère est belge.

My mother is Belgian.

Mes parents sont gentils.

My parents are kind.

Comment s'appelle ton frère ?

What is your brother called?

Son amie est canadienne.

His friend (f.) is Canadian.

Traps to avoid

~~Marc parle avec son sœur.~~
Marc parle avec sa sœur.
English chooses his or her from the owner, so learners think "Marc, so son". French looks only at the noun: sœur is feminine, so sa.
~~Ma amie s'appelle Inès.~~
Mon amie s'appelle Inès.
Amie is feminine, but ma before a vowel is impossible to say smoothly. Before a vowel sound, ma, ta, sa become mon, ton, son, and the gender doesn't change.
~~Mon parents sont belges.~~
Mes parents sont belges.
Mon only goes with one masculine noun. With any plural, masculine or feminine, you need mes, tes or ses.

Drill it

From the lesson My family. Type each answer, no multiple choice. 20 drills on this rule.