应
yīng · HSK 4
should
sounds like 'ying' — echoes 'yearning' to do what one ought
应 (yīng) means should/ought. The pronunciation 'ying' echoes English 'yearning' — a yearning to do what one ought. Also appears in 应该 (yīnggāi, should) and 应当 (yīngdāng, ought to).
应 — 广 (shelter) + 心 (heart) + 隹 (bird)
Originally written 應, this character combined a phonetic component with 心 (heart) to suggest 'responding from the heart' or 'answering a call'. The simplified form 应 keeps the top portion. Over time it broadened from 'respond/answer' to also mean 'should' or 'ought to'.