CRITICISE AND PRAISE

I found him wanting= que le falta algo, deficiente en algo
Decry= menospreciar

to run down somebody or  something (criticise unfairly)
To bite back =  to  hit back
To rub something in (informal = restregar a alguien algo).

What are you playing at?
 To have a go at samebody

To air dirty laundry
To harp on petty disputes

To show off

To speak highly of sb