Déterminants possessifs in French are equivalents of "my", "your", "his", "her" etc. in English. They are used to show the belonging of an object or of a person to someone .

The choice of déterminants possessifs depends on the gender and the number of subsequent noun and the quantity of possessors.

The choice of déterminants possessifs:

• = "my"
~ if a following noun is singular and masculine =>"mon"
~ if a following noun is singular and starts with a vowel or silent "h" regardless of gender =>"mon"
~ if a following noun is singular and feminine =>"ma"
~ if a following noun is plural =>"mes"

• = "your" (singular)
~ if a following noun is singular and masculine =>"ton"
~ if a following noun is singular and starts with a vowel or silent "h" regardless of gender =>"ton"
~ if a following noun is singular and feminine =>"ta"
~ if a following noun is plural =>"tes"

• = "his", "her","its" (only one possesor)
~ if a following noun is singular and masculine =>"son"
~ if a following noun is singular and starts with a vowel or silent "h" regardless of gender =>"son"
~ if a following noun is singular and feminine =>"sa"
~ if a following noun is plural =>"ses"

• = "our"
~ if a following noun is singular regardless of gender =>"notre"
~ if a following noun is plural =>"nos"

• = "your" (plural or courtesy form / vouvoyer)
~ if a following noun is singular regardless of gender =>"votre"
~ if a following noun is plural =>"vos"

• = "their" (some possesors)
~ if a following noun is singular regardless of gender =>"leur"
~ if a following noun is plural =>"leurs"

!!! If before a noun there is a déterminant possessif, so any article must be omitted.

Mon / Ton / Son papa (ms)
Mon / Ton / Son oncle (ms)
Mon / Ton / Son amie (fs, aber beginnt mit Vokal)
Mon / Ton / Son histoire (fs, aber beginnt mit einem stummen "h")

Ma / Ta / Sa grand-mère (fs)


Mes / Tes / Ses devoirs (mp)
Mes / Tes / Ses oncles (mp)
Mes / Tes / Ses amies (fp)
Mes / Tes / Ses histoires (fp)
Mes / Tes / Ses grand-mères (fp)


Notre / Votre papa (ms)
Notre / Votre oncle (ms)
Notre / Votre amie (fs)
Notre / Votre histoire (fs)
Notre / Votre grand-mère (fs)


Nos / Vos devoirs (mp)
Nos / Vos oncles (mp)
Nos / Vos amies (fp)
Nos / Vos histoires (fp)
Nos / Vos grand-mères (fp)


Leur papa (ms)
Leur oncle (ms)
Leur amie (fs)
Leur histoire (fs)
Leur grand-mère (fs)


Leurs devoirs (mp)
Leurs oncles (mp)
Leurs amies (fp)
Leurs histoires (fp)
Leurs grand-mères (fp)


Comparison:

Il aime sa grand-mère (nur ein Besitzer hat eine Grossmutter)
Il aime ses grand-mères (nur ein Besitzer hat mehrere Grossmütter)

Ils aiment leur grand-mère (mehrere Besitzer haben eine Grossmutter)
Ils aiment leurs grand-mères (mehrere Besitzer haben mehrere Grossmütter)