Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant:  Human: What language should I learn if I want to create Android apps?

Assistant: 
The primary language used to create Android apps is Java. Additionally, you may also use Kotlin, which is a more modern and concise programming language that is fully compatible with Java and is becoming increasingly popular among Android developers. Native Android applications are mainly written in Java or Kotlin. Java was the original language, but Google introduced later Kotlin and it's the language preferred nowadays.

You can also develop Android applications with other languages. There are part of high performance applications written in C/C++. In addition, there are cross-platform frameworks that use other languages, mainly JavaScript. If you’re interested in designing mobile apps on the Android platform, Java might be right for you. Right now you could learn
1. Java
2. Kotlin
3. C++
4. C#
5. Python
6. HTML, CSS, JavaScript
7. Dart 
8. Corona

it’s upon you to make the correct choice of language on the basis of your objectives and preferences for each individual project. English, most of the documentation is originally written in English. Also there's a lot of content in Youtube in English to learn Android, of course if you already know English you shouldn't learn anything.