[dewfull]

S ; Subject
V ; verb
Do ; Direct Object

S + V -> I sleep, I walk, She went and so on.
In this case, a verb doesn't need an object.

S + V + DO -> like, want, have and so on.
These verbs are called transitive verb.
They need Objects to complete the sentences.
I like you.
I want some water.
I have lunch.