Identify the tone of a word said by different voices at different speeds. Eight sessions over two weeks was enough in Wang et al.; your pace is yours.

달 · 딸 · 탈: lenis, tense, aspirated. The cue is mostly pitch on the vowel, so this opens once your ear is tuned to pitch.

Hear a native voice, say it back, and see your pitch line over theirs. A transcription round-trip tells you whether a listener would have heard the right word.

367 Sino-Xenic compounds: simplified target, traditional as the bridge to the kanji you know, pinyin, hangul, kana, Vietnamese, every reading playable and sayable.

200 cards. English words with their Latin source and the cognate in Spanish, Portuguese, French, Italian, Romanian and Catalan.

206 cards. Native English words with their Proto-Germanic source and the cognate in German, Dutch, Swedish, Danish, Norwegian and Icelandic. Watch for meanings that drifted: deer / Tier (animal).

150 cards. Russian, Ukrainian, Polish, Czech, Serbian and Bulgarian words from one Proto-Slavic source, Cyrillic with a transliteration.

150 cards. Arabic, Hebrew and Maltese words built on the same three-consonant root; Maltese writes them in Latin letters: salām / shalom / sliem from š-l-m.

274 cards. Turkish, Azerbaijani, Uzbek, Turkmen and Kazakh words from one Turkic source: su / suv / suw / су.

119 cards. Finnish, Estonian and the few Hungarian words that survived 3,000 years apart: kala / kala / hal (fish).

150 cards. Hindi, Urdu, Bengali, Marathi, Punjabi and Gujarati words from one Sanskrit source, each script with a transliteration.

130 cards. Persian, Tajik, Kurdish and Pashto words from one Iranian source, many with English cousins: dokhtar / daughter.

130 cards. Irish, Scottish Gaelic and Welsh. The hook is the k / p split: ceann / ceann / pen (head).

100 cards. From Madagascar to Hawaii: Indonesian, Malay, Tagalog, Malagasy, Māori and Hawaiian. lima = five in most of them.

120 cards. Native Tamil, Malayalam, Kannada and Telugu words (no Sanskrit loans), each script with a transliteration.

99 cards. Swahili, Zulu and Xhosa: the noun-class prefix changes, the stem stays. mtu / umuntu / umntu (person).

120 cards. Words Persian, Turkish, Urdu, Hindi, Swahili and Malay all borrowed from Arabic: kitāb / kitap / kitabu (book). The western cousin of the Sino-Xenic bridge.

100 cards. Words Thai, Khmer, Lao, Indonesian and Malay borrowed from Sanskrit and Pali: bhāṣā → phasa / bahasa (language).