"does" / "did" / "will" show the verb's tense ("know") in your example.
`not only` <VERB> _____ `but also` _______
is a standard English phrase.
`not only does` _____ `but also` ______ : PRESENT
`not only did` ______ `but also` _______ : PERFECT
`not only will` ______ `but also` _______ : FUTURE
`not only will` __ `have` ____ `but also` _______ : FUTURE PERFECT
Examples:
1) "not only does the cat sleep, but also it sleeps"
2) "not only /did/ each object know it was being logged, but also they /updated/ their status"
3) "not only will we build schools, but also we will help families."
Notice that in 2) "did" and "updated" are both in the perfect tense. Don't mix verb tenses here. I will understand but, it will sound awkward.
Some people switch and "also":
"not only does the cat eat, but it also sleeps"
Some people remove the pronoun:
"not only does the cat eat, but also sleeps."
Both are fine to me, this sounds more colloquial.