断言的英文：
affirm
assertion

参考例句：

Warning and assertion
警告和断言

On those numbers alone, the smart mobile phone revolution looks unstoppable.
仅从上述数字即可断言，智能移动电话的革命势不可挡。

Claggart seeks an interview with Vere and alleges that Billy is involved in a mutinous conspiracy.
克拉加特求见维尔，断言毕利卷入了哗变阴谋。

The decision or pronouncement made.
决定，断言作出的决定或断言

He swore (that) she was insane.
他断言她疯了。

A woman predictor;a woman soothsayer.
女预言家;女断言家

He claimed the election was rigged.
他断言选举有假。

The prophet's claim is proved to be wrong.
先知的断言被证明是错误的。

To proclaim or assert;declare.
宣称或断言;宣布

I aver that I have spoken the truth.
我断言，我说了真话。

affirm是什么意思：
v. 断言，肯定，证明，证实，申明

take the affirmative
站在赞成的一方

affirmation of contract
批准合同

They required her affirmation of the fact.
他们要求她证实那一事实。

This received opinion is piously affirmed.
这个被普遍承认的观点已经得到值得嘉许的肯定。

All the votes are in the affirmative.
全体投票赞成。

assertion是什么意思：
n. 断言，声称；主张；坚持

This is an assertive sentence.
这是一个论断句。

He has not a vestige of evidence for this assertion.
他没有丝毫证据证明这个论断。

She asserted the charge to be incorrect.
她声称这个命令是不正确的。

Challenge a claim, an assertion, a verdict
对某要求、主张、判决质疑

A bare assertion is not necessarily the naked truth.
坦率的主张未必就是坦白的事实。