I am from Japan, so there would be some errors of my English below.
The pop-up message in a web application we are developing
"Are you sure you want to execute delete this data?" ...(1)
It appears when a user choice the data they want to delete from a database and then press the "Delete" button. I pointed out a grammatical error because there are two verbs EXECUTE and DELETE in a row. However,my boss said the word "to" of infinitive verbs is sometimes left out so the (1) sentence above was originally
"Are you sure you want to execute to delete this data?"...(2)
So he said (1) is correct.
I think (2) is not grammatically incorrect but sounds too much, so I want to say
"Are you sure you want to delete this data?"...(3)
Which is the most correct and natural, (1),(2)or(3)? And please show me some examples in which the word "to" of the infinitive can be left out from sentences.