Hi Gregg,
Thank you for reaching out. I appreciate your interest in knowing if the Galaxy Watch 4 can send/receive messages and make/answer calls while paired with a phone. To answer your question, the device has that feature.
Please see its user manual on Page 42-44 for some tips on how to make and answer calls:
https://downloadcenter.samsung.com/content/UM/202109/20210929010214001/WEA_R89X_R88X_R87X_R86X_EN_UM_071621_FINAL_AC.pdf
Also, on Page 40-41 to view messages:
https://downloadcenter.samsung.com/content/UM/202109/20210929010214001/WEA_R89X_R88X_R87X_R86X_EN_UM_071621_FINAL_AC.pdf
You may also visit this link on an article for more tips under the "Make and answer calls on your watch" section:
https://www.samsung.com/us/support/answer/ANS00061408/
Should you need more assistance, you may reach us via the following for immediate support:
1. Samsung Community: https://us.community.samsung.com/t5/Samsung-Community/ct-p/us
2. Facebook Messenger: http://m.me/samsungsupport
3. Twitter: https://twitter.com/messages/compose?recepient_ id=18768513
Reference Number: 1144241364
Thank you for choosing Samsung. Have a great day!
^Chrystel