Not all fields translated

Hi,

I activated a few days a go the plugin Polylang to make my theme Trego multilanguage. It doesn’t translate all fields of the theme and woocommerce. e.g.http://perlajoyas.com/product-category/juwelen/oorbellen/
This link should all be translated in Dutch but you still see English words(theme).
Is Polylang compatible with my purchased theme Trego?
Or do I just have to add the necessary language files of my theme?

Thx a lot,
veerle

https://wordpress.org/plugins/polylang/