Part of the difference between children learning something and adults learning something is that we have trouble achieving Beginner's Mind.
Finding techniques that work fine to be remedial or even insulting makes you get into your own way. In the extreme case, how do you fill a cup which is already full?
Less philosophically, each language you master gets its own language center in your brain, just as each finger you can control individually maps to an identifiable region of your motor cortex (and if you can't control your pinky, it's because they've blended together). Translating back and forth is a crutch for most, and a separate skill for others (eg, professionals). That's why when you ask your friend, "what did those guys say in the background?" you get something vague back. Nothing translates directly, idioms doubly or triply so.
What did that guy say? He said he's really mad at that other guy, (using a lot of colorful language), and I can say "he's mad" or we can go into why calling someone a dog/goat/cow/fish in this language is one step down from saying bad things about their mother.