German has two words for “you.” Choosing the right one is about respect and relationship, not grammar difficulty. Getting it wrong rarely offends badly, but getting it right makes you sound genuinely at home in the language.
The simple rule of thumb
- du — family, friends, children, animals, fellow students, and usually colleagues your own age once invited.
- Sie — strangers, older people, officials, shop and service staff, and anyone in a professional setting until they offer the du.
- When unsure, start with Sie. It's easy to move from Sie to du; the reverse is awkward.
The verb changes with the pronoun
Wie heißt du?
What's your name? (informal)
du + -st ending
Wie heißen Sie?
What's your name? (formal)
Sie + -en ending, capital S
Hast du Zeit?
Do you have time? (informal)
Haben Sie Zeit?
Do you have time? (formal)
Tipp · Formal Sie is always capitalised, everywhere in the sentence — that capital letter is how readers tell it apart from sie (she/they).
✗Können du mir helfen? (to a stranger)
✓Können Sie mir helfen?
Address strangers with Sie and the -en verb form.