announce 后接名词或代词或that宾语从句,有"通知"的意思,而declare除接上面结构以外还可接复合宾语等结构.
declare 经常用于正式场合.指“清楚,公开让人知道”.
state 陈述;声明;说明
The witness stated that she had never seen Mr.Smith.
证人宣称她以前从未见过史密斯先生.