declare 有两个核心用法：① 「正式宣布，声明」：declare war (on)（宣战）；declare independence（宣布独立）；declare sb./sth. to be（宣布…为：declare the election void = 宣布选举无效）；declare that（声明：declare that all are equal = 声明所有人平等）；② 「申报（税务/海关）」：declare an income（申报收入）；declare goods at customs（在海关申报货物）。名词：declaration（宣言；申报：the Declaration of Independence = 独立宣言；a tax declaration = 纳税申报）。辨析：declare（正式宣布，有法律或官方效力）vs. announce（宣布，通知：announce a policy = 宣布政策；更广泛，包括非正式场合）vs. proclaim（宣告，更庄严：proclaim a holiday = 宣告假日；proclaim one's innocence = 宣告无辜）。
释义
1
v.正式宣布，声明
The prime minister declared a national emergency following the catastrophic flooding that had left thousands of residents without shelter.
首相在灾难性洪水导致数千名居民无家可归后宣布了全国紧急状态。
2
v.申报（向官方）
All travellers entering the country are legally required to declare any items that exceed the duty-free allowance.
所有进入该国的旅行者依法必须申报任何超过免税额度的物品。
语感
declare war（宣战）；declare independence（宣布独立）；declare an income（申报收入）；declaration（宣言；申报）；declare sth. to be（宣布某事为…）
正式宣布，声明（declare war = 宣战）申报（向官方：declare income = 申报收入）
高频搭配：declare war on sth./sb.（宣战：declare war on terrorism = 向恐怖主义宣战）；declare independence（宣布独立：declare independence from = 宣布脱离…独立）；declare sth. illegal / void / a success（宣布某事非法/无效/成功）；declare that（声明：declare that the results are final）；declare an income / assets（申报收入/资产）；declare goods at customs（在海关申报货物）；declaration of（…的宣言/申报：a declaration of intent = 意图声明；customs declaration = 海关申报）；辨析：declare（正式宣布，有法律/官方效力：declare war/independence = 具有政治效力）vs. announce（宣布，通知：announce a new policy = 宣布新政策；更广泛，可非正式）vs. proclaim（宣告，庄严：proclaim a republic = 宣告共和国成立；比 declare 更庄严，多用于重大历史场合）。
陷阱
⚠️declare（有官方效力）vs. announce（通知/宣布）——正式程度不同
The head of state declared a state of emergency, granting additional powers to the security forces and suspending certain civil liberties.
✗
declare = announce（完全等同）
✓
declare（正式宣布，有法律/政治效力：declare a state of emergency = 正式宣布紧急状态，具有法律效力；declare war = 具有宣战的国际法效力）；announce（宣布，通知，较广泛：announce the results = 公布结果；announce a new product = 宣布新产品；不一定有法律效力）；此句 declare a state of emergency = 具有法律效力的正式宣布，用 declare 正确；× announce a state of emergency 在正式语境不精确
All passengers are required to complete a declaration form before passing through customs, listing any restricted goods they are carrying.
所有乘客须在通过海关前填写申报表，列出他们携带的任何受限物品。（declaration form = 申报表，此用法正确）
declaration form（申报表）是标准说法；customs declaration = 海关申报；declaration 在此义= 申报，与「宣言」义不同；此句 a declaration form = 申报表，正确；注意：declaration 在政治历史语境 = 宣言（the Declaration of Independence = 独立宣言）；在海关/税务语境 = 申报（customs declaration = 海关申报）；两者均正确，语境决定义项
✓
All passengers are required to complete a customs declaration form before passing through customs.
所有乘客须在通过海关前填写海关申报表。（customs declaration，申报义）
近义辨析
declarevsannounce
declaredeclare（正式宣布，有官方/法律效力：declare war = 宣战（法律效力）；declare a state of emergency = 具有法律授权的宣布）announceannounce（宣布，通知：announce a new initiative = 宣布新举措；announce the winner = 宣布获胜者；比 declare 更广，包括非正式场合，不一定有法律效力；较中性）
The court declared the election results invalid on the grounds that voting procedures had not been properly followed.
法院宣布选举结果无效，理由是投票程序未被正确遵循。
The company announced record profits for the third consecutive quarter, sending its share price sharply higher.
该公司宣布连续第三个季度创纪录的利润，使其股价大幅上涨。
写作加分
✨ 加分词
替换：say officiallyannouncemake public
政治话题政策分析话题历史话题
普通
The government officially said that the country was in a state of emergency.
政府正式宣布该国处于紧急状态。
加分 ✨
When a government declares a state of emergency, it typically invokes extraordinary powers that suspend normal democratic processes — a measure that, if prolonged, poses serious risks to civil liberties.