1.assert “宣称，坚持”，指不管事实如何，主观自信地宣称

We encouraged him to assert his view of the matter.
我们鼓励他坚持自己对此事的看法。

2.claim “声称，主张”，往往表示说话者反对或不同意某一观点，或指根据某种规定提出的要求或主张

The matter claimed our serious attention.
这件事需要我们认真注意。

3. allege “宣称，断定”，指在无真实凭据情况下宣称

The police alleged that the man was murdered but they have given no proof.
警方声称这男子是被谋杀的，但未提出任何证据。

4. answer for 对……负责

I agree but I can't answer for my colleagues.
我同意，但是我不能代表我的同事们。

5. in answer to 作为回答，响应

In answer to my shouts people ran to help.
听到我的呼叫声，人们就赶来救我。