pet

Compared meaning: much loved or especially liked (adjective).

比较义项：钟爱的，特别喜爱的（形容词）。

• precious

  Describes something cherished for deep emotional or sentimental value, often irreplaceable; typically modifies objects, memories or people and can also be used predicatively.

  形容因深厚的情感或纪念意义而被珍视的事物，往往独一无二、无法替代；通常修饰物品、回忆或人，也可作表语。

  Her late mother's necklace is precious to her, though it isn't worth much money.

  她已故母亲留下的项链对她来说很precious，尽管它并不值多少钱。

• pet 本词

  Almost always placed before a noun in fixed expressions like 'pet project' or 'pet theory', showing a personal, sometimes quirky favorite; rarely used predicatively.

  几乎总是放在名词前，用于“pet project”（钟爱的项目）、“pet theory”（偏爱的理论）等固定搭配，表示个人特别偏爱、略带随意的喜好；这个意义上很少作表语。

  Cutting the team's paperwork in half has become her pet project this year.

  今年，把团队的文书工作减少一半成了她的pet项目，也就是她特别偏爱、上心的项目。

• dear

  Expresses warm affection, especially toward people; common in letter or email openings such as 'Dear Sir' and phrases like 'my dear friend'; softer and more intimate than the others.

  表达温暖的情感，尤其用于对人的称呼；常见于书信或邮件开头，如“Dear Sir”（亲爱的先生），也用于“my dear friend”（我亲爱的朋友）之类的说法；比其他几个词更柔和、更亲密。

  She began the letter, 'Dear Grandma, I think about you every single day.'

  她在信的开头写道：“Dear 奶奶，我每天都想着你。”

• favorite

  Implies choosing one thing as the most liked among several alternatives; neutral in tone and combines freely with everyday nouns like food, color or song.

  暗示在多个选项中挑出最喜欢的一个；语气中性，可自由搭配食物、颜色、歌曲等日常名词。

  Chocolate ice cream has always been his favorite dessert on hot summer days.

  巧克力冰淇淋一直是他在炎热夏日里的favorite甜品。

These four words mean deeply loved. Precious: cherished for emotional value. Pet: used before a noun, as in pet project. Dear: warm affection, as in letters. Favorite: liked best among choices. This excludes precious (costly), pet (an animal), dear (expensive), and favorite (a noun).

这四个词都可表示“深受喜爱的”，但语气和用法差别很大：precious强调因情感或纪念意义而倍加珍视，多修饰物品、回忆或人；pet几乎只用在project、theory等名词前的固定搭配里，表示个人特别偏爱、略带随意的喜好；dear侧重对人的温暖情感，常用于书信称呼；favorite则是在多个选项中挑出最喜欢的一个，语气中性。这里不比较precious表示“贵重的，稀有的”的义项、pet作名词“宠物”的用法、dear在英式英语中“昂贵的”的义项，以及favorite作名词“最喜爱的人或物”的用法。