1 指“军队”，既指“军队”的总称，也侧重指“陆军”。比较：navy（海军），air force （空军）

2 用作主语，谓语动词可单可复，整体考虑用单数，个体考虑用复数。

The army was/were wiped out.

这支军队被消灭了。

3 “参军”及相关说法。

join the army/go into the army/become a soldier/enter the army

注：以上均为终止性动词，不可与一段时间连用。

be in the army/be a soldier，表示状态，可与一段时间连用。

翻译：他参军10年了。

He joined the army 10 years ago.

He has been a soldier for 10 years.

He has been in the army for 10 years.