Sentence examples for who do from inspiring English sources

The phrase "who do" is grammatically correct and can be used in written English.
It is typically used as a question or as part of a relative clause. Example 1: "Who do you think will win the game tonight?" Example 2: "I don't know who do you want to invite to the party." Example 3: "The candidate who do we choose could have a major impact on the outcome of the election."