If you do decide to make an application, what you do is send it directly tom
这句话感觉语法错误 is send 两个动词怎么一起用了呢?
不定式作表语时,如主语部分含有实义动词do,且句子的时态为一般现在时或一般过去时(多为is或was),不定式可以带to也可不带to
(1)What we must do now is(to) find anther person to help us. (2)All he could do was (to) rush into the room.
如句子的动词时态不是一般现在时或一般过去时,作表语的动词不定式一般要带to (1)She knew that all she would have to do would be to stop crying.