Well, on the suggestions this may be my "subjective" "style". I.e., some people may use more often the translations in your flash-cards... That's why I just noted as blue, as the way you have these is not incorrect at all.
Like... I personally would say "un perro fiel" or "un marido fiel", but I would tend to use "un chico digno de confianza". That may just be my personal liking. As long as you understand you can get familiar with words and synonyms and if you start reading and listening to native Spanish speakers, you may notice what is more common in your area, and have your own criteria to choose.
At any rate, you are doing good. Keep it up!
