person

Compared meaning: a human being (noun).

比较义项：人，人类个体（名词）。

• individual

  Treats a person as a single unit set apart from a group, favoring formal, legal, or statistical contexts over casual speech.

  强调把某人当作与群体分开的单独个体看待，常见于正式、统计或法律语境，而非日常口语。

  The contract holds each individual liable for their own debts.

  合同规定，每一个人都要对自己的债务负责。

• person 本词

  The plain, all-purpose word for a human being, used in ordinary everyday speech without special formality or focus on mortality.

  这是指人的最普通、通用的说法，可以用于各种日常语境，没有特殊的正式感，也不强调死亡。

  There's a person waiting outside the door for you.

  外面有个人在等你出去见他。

• mortal

  Stresses that a human being will eventually die, typically used in literary, philosophical, or humorous writing contrasting humans with gods or immortals.

  强调人终有一死，常用于文学、哲理或幽默的语境，用来把人类和神明或不朽者进行对比。

  In the myth, the goddess fell in love with a mortal and faced tragic consequences.

  在这个神话故事里，女神爱上了一个凡人，因此不得不承受后果。

All three can mean 'a human being'. Individual sets a person apart from a group, in formal use. Person is the plain, everyday word for a human. Mortal stresses that a human will die, in literary writing. Not covered: individual as 'single', mortal as 'deadly'.

这三个词在表示“人、人类个体”时容易混淆：individual强调把某人从群体中单独拿出来看待，语气较为正式；person是最普通、中性的说法，日常最常用；mortal强调人终有一死，带文学或哲理色彩，很少用于普通场合。这里不比较individual作形容词表示“单独的，个别的”的用法，也不比较mortal作形容词表示“致命的”的用法。