Our plan is to keep the affair secret.这个句子是主系表结构吗?

问题描述:

Our plan is to keep the affair secret.这个句子是主系表结构吗?
如果是主系表结构,is是系动词,to keep the affair secret是表语还是keep the affair secret是表语?

此句如楼主所说为主系表结构
Our plan主语
is连系动词
to keep the affair secret.表语(动词不定式作表语)