affect

Compared meaning: to have an effect on something (verb).

比较义项：对某事产生影响、发生作用（动词）。

• impact

  Stronger and more formal; suggests a significant, large-scale or forceful effect; common in business, policy and news contexts, often paired with 'on'.

  语气更强、更正式；暗示显著的、大范围的或有力的影响；常用于商业、政策和新闻语境，常与“on”搭配。

  The new tax law will impact thousands of small businesses nationwide.

  这项新税法将影响全国数千家小企业。

• affect 本词

  More common and neutral; used for effects of any size, in both casual and formal speech; always directly transitive, never followed by 'on'.

  更常用、语气中性；可用于任何强度的影响，口语和正式场合皆可；总是直接及物，不与“on”连用。

  Loud music from next door affects my concentration at work.

  隔壁的嘈杂音乐影响了我工作时的注意力。

Affect and impact both mean to have an effect, but impact is stronger and more formal, suggesting a large effect, and usually followed by 'on'. Affect is more common and neutral, used for effects of any size. Impact's noun sense is not compared here.

这两个词在“影响”这一义项上意思相近，但语气强弱和使用场合不同：impact 语气更强、更正式，强调显著或大范围的影响；affect 是更常用的中性动词，日常和正式场合都可使用。impact 还可作名词（an impact），此处只比较其动词用法。

Compared meaning: to pretend to feel or have something (verb).

比较义项：假装（具有某种感觉或态度）（动词）。

• pretend

  The everyday, general word for any false appearance — used for actions, games, or feelings alike (pretend to be, pretend that); fits casual conversation and children's play.

  最日常、最通用的词，可用于任何假装的情况——动作、游戏或感觉皆可（pretend to be、pretend that），适合口语及儿童游戏场景。

  The kids pretend to be superheroes and run around the yard for hours.

  孩子们假装自己是超级英雄，在院子里跑来跑去玩上好几个小时。

• affect 本词

  Often describes putting on a manner or emotional air to impress others or seem a certain way (affect an air of calm), implying insincerity; more formal and literary than pretend.

  常指故意摆出某种情绪或姿态以给人留下某种印象（如affect an air of calm），暗示不真诚；比pretend更正式、书面化。

  He affected an air of calm before the interview, though his hands were shaking.

  面试前他刻意摆出一副镇定的样子，尽管他的双手在发抖。

• feign

  Formal and literary; strongly associated with fixed phrases like feign interest, feign illness, feign ignorance, suggesting a convincing, deliberate deception.

  书面、正式；常见于feign interest、feign illness、feign ignorance等固定搭配，强调刻意而逼真的欺骗表演。

  He feigned interest in her vacation stories, nodding along without really listening.

  他假装对她的旅行故事感兴趣，一边点头一边其实并没有真正在听。

Pretend, affect, and feign all mean to fake a feeling. Pretend is the common, general word for any false appearance. Affect and feign are more formal: affect means acting a manner to impress; feign means a convincing, deliberate deception. Affect also means 'influence'; not compared.

这三个词在“假装（某种感觉）”这个意义上很接近，但语体和搭配不同：pretend最口语化、适用范围最广，feign和affect更正式、书面化，feign强调逼真的欺骗表演，affect强调刻意摆出某种姿态给人留下印象。这里不比较affect的常见义项“影响”（如影响心情），也不比较pretend“冒称、觊觎（王位等）”的义项。