Moroccan Arabic (Darija) and French are the everyday languages; English is common in tourist hubs but thins out fast once you're off the main track. You don't need fluency — five or six words go a long way.
Salam (hello), shukran (thank you), afak (please), bslama (goodbye), and bghit... ("I want...") for ordering or asking for something will consistently earn warmer service and better prices than English alone.
If you speak any French, use it — it works almost everywhere, including with taxi drivers, shopkeepers and hotel staff, and is more broadly understood across the country than English, especially outside Marrakech, Fes and the coastal resort towns.
