know a thing or two about
To be experienced in; have a fairly considerable knowledge of.
Иметь опыт в чем-либо; иметь существенные знания о чем-либо.
Tom has dealt with many foreign traders; he knows a thing or two about stocks and bonds.
Jack has been working as a mechanic for years, and he knows a thing or two about cars.
Джек работал механиком долгие годы, и он понимает, что к чему в машинах.
tell a thing or two
To tell in plain or angry words; scold.
When John complained about the hard work, his father told him a thing or two.
If Bert thinks he would like to join the army, I'll tell him a thing or two that will make him change his mind.
thing or two
Facts not generally known, or not known to the hearer or reader; unusual or important information.
Mary told Joan a thing or two about Betty's real feelings.
A lot; much.
Bob knows a thing or two about sailing.