If you're a beginner, you're better off with a tutor who speaks your native language. This way, you can ask about anything that's not clear to you. Similarly, the tutor can explain things in detail so you understand things. But when you feel confident enough, it's a great idea to switch to a native speaker if you want to improve your spoken Arabic. Non-native speakers can phrase sentences correctly, but they just don't always sound natural. Non-native speakers use more complex words and constructions where native speakers would throw in a phrasal verb and say things in a simpler way.