Mandarin Chinese is the most widely spoken language in the world, used by over a billion people, mostly in China. When people say they're learning “Chinese,” they usually mean Mandarin, though China actually has many different languages and dialects.

Mandarin uses a writing system based on characters rather than an alphabet. Each character represents a word or part of a word, and there are thousands of them to learn. The same written characters can be read by people who speak different Chinese languages, which helps unite a huge, diverse country.

What makes Mandarin especially interesting (and challenging) is that it's a tonal language. The same sound can mean completely different things depending on whether you say it with a rising, falling, flat, or dipping tone. The syllable “ma” with a high level tone means “mother,” but with a rising tone it means “hemp,” and with a falling-rising tone it means “horse.” Get the tone wrong and you might accidentally say something completely different from what you intended.

In China, people often call it Putonghua, meaning “common speech.” It's the official language of China and one of the official languages of Singapore. A closely related standard form, called Guoyu (“national language”), is the official language of Taiwan.