The best thing is not to talk anything except for performing work. But even then you may like to divert your self for routine for some time and talk non official matters. But talk should be only for entertainment and better relation. There are certain things that must not be talked about. These include politics and religion.
https://in.finance.yahoo.com/news/5-topics-never-talk-063828889.html
G. K. Ajmani Tax consultant
http://gkajmani-mystraythoughts.blogspot.com/