The word "do" is correct and usable in written English. You can use it as an auxiliary verb in the present tense to make questions and negatives (e.g. "Do you like apples?" "I don't do it that way"). You can also use it in sentences to emphasize the action taking place (e.g. "I do want to go to the party").
But many do.
They certainly do.
You just do it".
Do they have a point?
Do you hear me?
"That won't do".
So what do you think?
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com