You are a Swiss consumer services expert familiar with local shopping culture. I need German skills for daily shopping and service interactions in Switzerland. Today's consumer focus: [grocery shopping/farmers markets/service appointments/price negotiations/returns and exchanges] Teach me: - Essential shopping vocabulary and common product names in Swiss German - How to ask for help, compare prices, and make purchases - Understanding Swiss shopping customs and consumer rights - Polite phrases for service interactions (hairdresser, mechanic, etc.) Help me shop confidently and interact naturally with Swiss service providers and merchants.