somewhat

Compared meaning: to a moderate degree, quite (adverb).

比较义项：表示程度的“相当／有点”（副词）。

• pretty

  Informal and mainly spoken; feels stronger and more casual than fairly or somewhat, and sounds out of place in formal writing.

  非正式，多用于口语；比 fairly 和 somewhat 语气更强、更随意，用在正式书面语中会显得不合适。

  It's pretty late already, so we should probably head home now.

  现在已经相当晚了，我们大概应该回家了。

• somewhat 本词

  More formal and often written; commonly precedes comparative forms or verbs of change, which pretty and fairly cannot naturally do.

  更正式，多用于书面语；常放在比较级或表示变化的动词前，而 pretty 和 fairly 通常不能这样用。

  The test results were somewhat better than we had expected.

  考试成绩比我们预期的稍好一些。

• fairly

  Neutral in register, common in both speech and writing; weaker than pretty and used before plain adjectives rather than comparatives.

  语域中性，口语和书面语都常用；程度比 pretty 弱，通常放在普通形容词前，而不是比较级前。

  The hotel room was fairly small, but it was clean and quiet.

  这间酒店房间相当小，但是干净又安静。

Pretty, somewhat, and fairly all show a moderate degree. Pretty is informal and spoken, too casual for formal writing. Somewhat is more formal and written, often before comparatives like 'somewhat better'. Fairly is neutral, common in speech and writing, used before plain adjectives.

这三个词都用来表示程度，比“很”弱，但语域和搭配不同：pretty 偏口语、语气较强，fairly 语域中性、强度居中，somewhat 偏书面、常与比较级连用。这里不比较 pretty 作形容词“漂亮的”的用法。

Compared meaning: to a small degree, a little (adverb).

比较义项：稍微、轻微地（adv.）。

• somewhat 本词

  More formal and often written in tone; typically precedes a comparative or evaluative adjective (somewhat surprising, somewhat different) rather than a verb or a plain measurement.

  语气更正式、更偏书面语；通常用在比较级或带有评价色彩的形容词前面（如somewhat surprising、somewhat different），不太用来修饰动词或单纯的度量。

  The weather today is somewhat colder than yesterday morning.

  今天的天气比昨天早上稍微冷一点。

• slightly

  More casual and common in everyday speech; often modifies measurable degree words like temperature, taste or amount, frequently pairs with 'too' (slightly too salty), and can directly modify verbs (slightly increased).

  更口语化，日常使用更常见；常修饰可测量的程度词（如温度、味道、数量），常与“too”搭配（如slightly too salty），也可以直接修饰动词（如slightly increased）。

  The soup tasted slightly too salty for my liking.

  这汤对我来说尝起来稍微有点太咸了。

Somewhat and slightly both weaken the word that follows, meaning a little. Somewhat is more formal, often before a comparative adjective. Slightly is more casual, often used with measurable things like temperature, and pairs with too, as in slightly too salty.

这两个词在“稍微、轻微”这个意义上非常接近，都用来削弱后面形容词或动词的程度，但语气和搭配习惯不同：somewhat更正式、偏书面语，常放在比较级或带评价色彩的形容词前；slightly更口语化，常与“too”连用表示轻微超出某个标准，也能直接修饰动词。