tough

Compared meaning: difficult to do or deal with (adjective).

比较义项：困难的，不容易做到或应付的（形容词）。

• challenging

  Emphasizes that a task tests or stretches someone's abilities in a stimulating way; often used approvingly, suggesting effort leads to growth rather than mere hardship.

  强调某件事以激励性的方式考验或锻炼一个人的能力，常用于褒义，暗示努力会带来成长，而不只是艰辛。

  She took a challenging new role that pushed her to learn skills she'd never used before.

  她接受了一份有挑战性的新工作，促使她学习了以前从未用过的技能。

• tough 本词

  Suggests a difficulty that demands endurance, toughness, or emotional strength; more informal and often implies hardship or strain rather than an opportunity for growth.

  暗示这种困难需要毅力、坚韧或情感上的力量来应对；语气更口语化，常暗含艰辛或压力，而不是成长的机会。

  Losing his job right before the holidays was really tough on the whole family.

  在假期前失业对整个家庭来说真的很艰难。

• hard

  The plainest, most common word for difficult; neutral and informal, used in everyday speech and fixed expressions without any special connotation.

  是表示“困难”最普通、最常用的词；语气中性、口语化，常用于日常表达和固定搭配中，没有特殊的感情色彩。

  I find it hard to say no to free food.

  我发现很难拒绝免费的食物。

• difficult

  More formal and neutral than hard; common in written or professional contexts, describing a task or situation as requiring much effort, without emotional coloring.

  比 hard 更正式、更中性，常用于书面语或正式场合，描述某件事需要付出很多努力，不带感情色彩。

  The committee found it difficult to reach a unanimous decision on the budget.

  委员会发现很难就预算问题达成一致意见。

All four mean difficult, but differ in tone. Challenging is positive: a task that tests and builds skill. Tough is informal, stressing hardship and endurance. Hard is the plainest, neutral word. Difficult is more formal than hard. Tough's sense of physically strong is not compared.

这四个词都可以形容“困难的”事情，但语气和用法不同：challenging 带褒义，强调考验并锻炼能力；tough 更口语化，强调需要毅力去承受艰辛；hard 是最普通、最中性的日常用词；difficult 比 hard 更正式，多用于书面或正式场合。这里不比较 tough 表示“坚韧的、不易折断”的物理意义。

Compared meaning: a rough or violent person (noun).

比较义项：粗暴或恶劣的人（名词）。

• tough 本词

  Describes a rough, physically intimidating person, often just tough-looking rather than a proven criminal; frequently used in the plural 'toughs' in casual or news writing.

  指外表粗野、有威慑力的人，未必真的犯过罪，语气不如thug强烈；常用复数形式“toughs”，多见于口语或新闻报道。

  A few neighborhood toughs hung around the corner store all evening.

  几个彪形大汉整晚都在街角小店附近闲晃。

• thug

  The strongest and most negative term, naming a violent criminal who uses force or threats, typically in muggings, gang violence or organized crime.

  语气最强烈、最负面，指使用暴力或威胁手段的犯罪分子，常见于抢劫、帮派暴力或有组织犯罪的语境。

  The thug pulled a knife and demanded the tourist's wallet.

  那个暴徒掏出刀子，逼游客交出钱包。

• punk

  Informal, especially American English, for a worthless, cocky young troublemaker; used almost like an insult and does not necessarily imply serious violence.

  非正式用语，尤见于美式英语，指自以为是、爱惹麻烦的废物青年，几乎带有侮辱意味，未必真的涉及严重暴力。

  Stop causing trouble, punk, or I'll call your parents.

  别惹麻烦了，臭小子，不然我就叫你父母来。

Tough, thug and punk all describe a rough or bad person. Tough describes someone physically intimidating-looking, not necessarily a criminal. Thug is the strongest word, naming a violent criminal who uses force. Punk is informal, American English, for a cocky, worthless young troublemaker.

这三个词在表示“粗暴或恶劣的人”时意思相近，但语气强弱和使用场合不同：tough多指外表凶悍的壮汉，thug语气最重、多指使用暴力的罪犯，punk则是非正式的贬称，多指爱惹麻烦的年轻人。这里不比较tough作形容词表示“困难的”、以及punk指“朋克音乐或风格”的用法。