son vs sont

Summary

son is a possessive adjective meaning "his/her/its" before a masculine singular noun (son frère) or before a feminine noun starting with a vowel (son école); sont is the verb être conjugated for ils/elles (ils sont là). Both are pronounced /sɔ̃/. Test: if you can replace the word with étaient (imparfait of être), it's sont; if you can replace it with mon or ton, it's son. (A third, unrelated word, un son, means "a sound.")

Explanation

Son and sont are homophones, both pronounced /sɔ̃/, but they come from entirely different grammatical families. Son is a possessive adjective: it agrees with the noun it introduces, not with the owner, and it means "his," "her," or "its" depending on context. It is used before a masculine singular noun (son frère = "his/her brother") and, importantly, also before a feminine singular noun that begins with a vowel or mute h, purely for pronunciation reasons (son école = "his/her school," not "sa école").

Sont is the third-person plural present-tense form of the verb être: ils sont, elles sont ("they are"). It is used exactly like any other conjugated verb, appearing after a plural subject and before an adjective, noun, or location: ils sont fatigués, elles sont médecins, ils sont là.

The substitution test is reliable and quick. Replace the word with étaient, the imparfait of être. If the sentence still works grammatically, the word is sont: Ils sont contents → Ils étaient contents ("They were happy") is fine, so it is sont. Now try replacing the word with mon or ton (other possessive adjectives). If that works, the word is son: Il aime son travail → Il aime mon travail is grammatically parallel, confirming the possessive son.

A second cue is what surrounds the word. Son always sits directly in front of a noun (or an adjective + noun): son ami, son grand jardin. Sont always sits directly in front of an adjective, a noun used as an attribute, a preposition phrase, or a past participle in a compound tense with être: elles sont parties, ils sont en retard.

Do not confuse the possessive son ("his/her/its," invariable in gender before a vowel-initial feminine noun) with the ordinary noun un son ("a sound," as in le son de la cloche or régler le son). Context makes this easy: after un, le, ce, or a number, son is a noun; directly before another noun with no article, it is the possessive.

In short: son introduces a noun (possessive, "his/her/its"); sont is a verb (être, ils/elles, "they are"). Swap in étaient to test for sont; swap in mon/ton to test for son. If the word precedes a bare noun, it is almost certainly the possessive son.

Examples

Il adore son frère et sa sœur. — He loves his brother and his sister. (son: possessive before the masculine noun frère (contrast sa before feminine sœur).)

Ils sont fatigués après le voyage. — They are tired after the trip. (sont: être, third-person plural; replaceable by étaient (ils étaient fatigués).)

Elle aime son école, même si ses profs sont stricts. — She loves her school, even though her teachers are strict. (son before the vowel-initial feminine noun école; sont as the verb are.)

Le son de sa voix est reconnaissable entre tous. — The sound of her voice is recognizable among all others. (un son here is the unrelated noun "a sound," not the possessive.)

Son frère et son amie sont déjà partis. — His brother and his friend have already left. (Direct contrast: son twice (before frère, before vowel-initial amie) then sont (être, plural).)

Common mistakes

Related rules

• Possessive adjectives (mon / ma / mes)
• être vs avoir
• on vs ont
• Noun gender (masculine / feminine)