How They Get Around Free Trade

I just read that a financial expert said President Trump knows nothing about currency manipulation; I don’t know anything about currency manipulation either. The expert says that the President thinks China is lessening the value of its currency, but the expert knows that China is actually increasing its  currency’s value. I on the other hand having no expert financial smarts think that all trading entities (nations ?) are manipulating the value of their currencies by keeping interest rates low so that their exports will flood the markets of the countries they want to export to.