Question

Until this morning, they kept the secret to themselves.

Okeep
Okeeped
Okeeping
no error​

Answer 1

Until this morning they KEPT the secret to themselves. There’s no error.

Answer 2

Until this morning, they keeped the secret to themselves.

Step-by-step explanation:

It is past tensted and kept as well so ya that's what I think

Hope this helps.