The particle の has multiple functions that often translate to the possessive ''s' in English. While it does show ownership, its role is broader in Japanese, marking (B) as something that belongs to or is associated with (A).

• あれは田中(たなか)さんの猫(ねこ)です。
  That over there is Tanaka-san's cat.
• 来週(らいしゅう)の月曜日(げつようび)。
  Next week's Monday. (This is a more literal translation, but shows how 'Monday' is an attribute of 'next week' in Japanese)

The first example clearly demonstrates の indicating possession, while the second example illustrates its use in showing a more general connection between (A) and (B).

Additionally, の can sometimes take the place of the particle が to mark the subject within a clause. The particle が is explained in its own dedicated grammar point.

• 彼(かれ)が描(か)いた絵(え)はきれいです。
  The picture he drew is beautiful.
• 彼(かれ)の描(か)いた絵(え)はきれいです。
  His drawing is beautiful.

These two sentences are a bit more complex as they involve modifying nouns, but we will explore that topic very soon!

Caution

While の typically follows a noun, it has another important function where it can turn a verb or an entire phrase into a noun. This grammatical process is known as nominalization. You can learn more about this in the の - Nominalization lesson.