One way to "solve" the tonality issue with Mandarin would be to increase the number of permitted phonemes or phoneme pairs and turn as many monosyllabic words a

One way to "solve" the tonality issue with Mandarin would be to increase the number of permitted phonemes or phoneme pairs and turn as many monosyllabic words as possible into polysyllabic ones. To some extent, the latter process has already taken place in the real world with the transition from classical Chinese. Pair this with a Hangul-like script or Bopomofo redesigned from the ground up and you've indeed got yourself a hypothetical tool of communicative beauty. Amusingly enough, English has its own tonal-equivalent learning problem in the form of phoneme stress. One of the final bosses for non-native but highly fluent speakers is the ability to never mess up the stress on certain words.