"Come say hi" is correct and can be used in written English. It is a friendly invitation to come and speak or greet someone. For example, "Hey everyone, come say hi to our new customer service team!".
Come say hi!" They ran over in a happy little tumbling blur.
Come say hi!" It helps to have new employees start together At ZocDoc, groups of new employees have lunch with the executive team.
Come say hi.
Snap a geo-tagged photo of what you're up to and a fellow Sidewalker might come say "Hi!" Sidewalk is now available for iOS and Android, but is only operating in San Francisco for now.
If penguins come say 'hut hi'.
A little boy who charmed his teachers at preschool and ran first to his sister at pickup every day to give her a huge hug before coming to say, "Hi Mommy!
He would come home say hi, kiss me on the cheek and go right to his computer until he came to bed.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK