Agreed. If you can't ask for a bus ride in a language, chances are you need to practise it more.
For example: I know all the colours in the world in German, and a few of the useflull verbs, such as the verb that is watching TV and listening, but, if I went to Germany, I wouldn't be able to ask for the washroom.
But, on the other hand, I went to a French school for eight years, and can ask for a Mocha, Double Chocholate, whippedcream with extra caramel croissant in France.