haben or sein?

The classic Perfekt trap. A helper question for your A1 verbs: does the verb take you somewhere else, or change your state?

• Yes → usually sein (gegangen, gefahren, gekommen — and aufgestanden: from lying to up)
• No → usually haben (gegessen, gekauft, geschlafen)

Plus the odd one out you already know: bleiben takes sein.

It is a helper, not a complete rule — learn each new verb together with its helper.