jou or jouw? A quick rule

Jou and jouw sound the same but do different jobs. Jou means you as the person an action reaches (Ik bel jou — I'm calling you). Jouw means your, marking something as belonging to you (jouw telefoon — your phone). The only difference on paper is the final w.

Ask what the word points to: a person (you) or a possession (your). If it means your and sits before a noun, write jouw with a w; if it means you and never owns the next word, write jou.

1. Try replacing the word with your in English. If your fits (your book), it is jouw: jouw boek.
2. If instead you fits — the word is a person being seen, called, or given something — it is jou: Ik geef het aan jou (I give it to you).
3. A second check: jouw is always followed by a noun it belongs to (jouw huis, jouw idee). jou is not.

• jou — as the object of a verb: Ik heb jou gisteren gebeld. (I called you yesterday.)
• jou — after a preposition such as voor, aan, met, van: Ik ga met jou mee. (I'll come with you.)
• jouw — as a possessive before a noun: Waar is jouw jas? (Where is your coat?)

Jou and jouw are the full forms; in casual speech both often shrink to the reduced je: je telefoon (your phone) and ik zie je (I see you). The full forms carry weight on the person when you want emphasis — Dat is jóuw probleem, niet het mijne. (That's your problem, not mine.) — but they are not only for emphasis. After a preposition the full jou is the neutral, unmarked choice (Dit is voor jou. — This is for you), and in careful writing jouw is routinely used to make clear whose something is.

The usual slip is writing jou where a noun follows: jou boek is wrong. If the next word is owned — a book, a house, an idea — it must be jouw boek. The reverse slip, jouw standing alone after a preposition (voor jouw), is also wrong: with no noun to own, it is voor jou.

The polite you works the same way one step up in formality: u is the object (Ik zie u) and uw is the possessive (uw paspoort), following the exact jou / jouw pattern. See the formal u.