The four tones, and the light one
Mandarin syllables carry a pitch shape, and the shape changes the word. Lin says the same syllable, ma, four ways:
In Taiwan the third tone is usually just low, without the rise at the end that textbooks draw, which is why "One syllable" plays each one alone. The neutral tone only turns up on a syllable after another one, so "Second of two" plays two-syllable words and asks about the second.
How to read pinyin
Pinyin writes Mandarin sounds with Latin letters, but several letters don't sound the way an English speaker expects. These are the ones to learn first.
Initials that surprise people
Vowels that change
Where the tone mark goes
On a or e if there is one (hǎo, xiè), on the o of ou (gǒu), and otherwise on the last vowel (liù, guì). No mark means the neutral tone. You can also write tones as numbers after each syllable, ni3 hao3, which the pinyin to zhuyin converter reads too.
Pinyin and zhuyin
Taiwan writes the same sounds in zhuyin, its own 37-sign alphabet, and people there learned their sounds that way, so it's worth reading both. The second game here pairs them: ㄓㄤ is zhāng, ㄐㄧㄤ is jiāng. It picks tones at random, so it's spelling practice: not every syllable is a word in every tone. Start the signs themselves in the zhuyin trainer.
In the Bopomo app every word you learn has its tones drawn as lines over it, and you say it out loud to Lin before you move on. Join the waitlist.
Questions
How many tones does Mandarin have?
Four, plus a light neutral tone: first (high and level), second (rising), third (low), fourth (falling) and the neutral tone on some syllables after another one, like the second ma in 媽媽.
Why are some clips one word and not a single syllable?
The neutral tone never stands alone, so it can only be heard after another syllable. "Second of two" plays real two-syllable words and asks about the second one, whose tone doesn't shift in speech the way the first one's can.
Is the voice a real person?
Yes: every clip is Lin, the tutor in the Bopomo app, with a Taiwan accent. There's no computer voice on this page.
I'm tone-deaf. Can I still learn the tones?
Almost certainly. Tones are about the shape of your voice, which you already use for questions and surprise in English. Ten minutes a day of hearing and choosing is how most learners get there.
Should I learn pinyin or zhuyin?
For Taiwan, learn zhuyin: it's what you'll see there and it takes about a week. Most dictionaries and courses use pinyin, so most learners end up reading both.