「Illegal」和「unlawful」兩個字乍看之下意思好像都代表「非法的」，但它們之間其實存在著一些細微的差別。簡單來說，「illegal」比較常用，也更廣泛地指任何違反法律的行為；而「unlawful」則帶有更正式、更嚴肅的語氣，通常指違背法律精神或道德規範的行為，有時甚至暗示著不公正或不合理的成分。

首先，讓我們看看一些例子：

• Illegal parking: 違規停車 (wéiguī tíngchē) This refers to parking in a place where it's prohibited by law, a common and relatively minor offense. Here, "illegal" is perfectly suitable.

• Unlawful seizure of property: 非法佔有財產 (fēifǎ zhàn yǒu cáichǎn) This implies a more serious violation of the law, possibly involving abuse of power or a significant breach of someone's rights. "Unlawful" emphasizes the unjust nature of the act.

• It is illegal to drive under the influence of alcohol. 開車酒駕是違法的。(kāichē jiǔjià shì wéifǎ de.) This is a clear and straightforward statement of a legal prohibition. "Illegal" is the more natural choice here.

• The court declared the contract unlawful. 法院宣告該合約無效。(fǎyuàn xuāngào gāi héyuē wúxiào.) The word "unlawful" highlights that the contract wasn't just technically against a specific law, but fundamentally flawed and therefore void.

再舉一個例子來區分兩者的語氣差異：

• It is illegal to litter. 亂丟垃圾是違法的。(luàn diū lèsè shì wéifǎ de.) (比較口語化)
• It is unlawful to dispose of hazardous waste improperly. 非法傾倒有害廢棄物是違法的。(fēifǎ qīngdǎo yǒuhài fèiqìwù shì wéifǎ de.) (比較正式、嚴肅)

總之，「illegal」較為普遍，適用於各種違法行為；而「unlawful」則更正式，暗示著行為的不公正或不合理。 在日常生活中，「illegal」已經足夠應付大多數情況。

Happy learning!