當他們成熟時

當他 dangˉ taˉ

(When he) When he

當他們 dangˉ taˉ men˙

(When they) When they

他們 taˉ men˙

(Their, Them, They) They, Them, Their

成熟 chengˊ shuˊ

(Mature) Mature

時 shiˊ

Time, At that time, Fashionable, Sometimes, Era, Season, Epoch