Only then does/do

[Offroad]

Dear teachers

Do these sentences read well?

Only then does he start to speak.
Only then does it begin to increase.
Only then can we travel back home.
Only then will I meet them at hospital.

Thank you

[SlickVic9000]

(Not a Teacher)

They're all fine, except for the second one:

"Only then does it begin to increase."

I don't think you meant to write "being".

[Offroad]

(Not a Teacher)

They're all fine, except for the second one:

"Only then does it begin to increase."

I don't think you meant to write "being".

It's a typo. Thank you.