Nauka języka jest jak.... budowa domu.
Takie porównanie pojawiło się w pewnej bardzo fajnej książce do nauki hiszpańskiego.
Fajnie porównane, tym bardziej, że wiele osób często zapomina o gramatyce twierdząc, że słownictwo to wszystko.
OK, a więc tak:
Builing a house is a wonderful analogy for learning a language for many reasons. First, there are the twin dichotomies of structure-decoration and grammar-vocabulary. Then, there is the realisation of their independence: each part helps to define and enhance each other. At first, the process is foundation-heavy (structure/grammar), with less emphasis on decoration/vocabulary: The prettiest sofa won't look good if the floor isn't level, and a million-dollar sink is a bowl with a hole if the plumbing doesn't work. But once the foundation is laid, the walls are in place, and the house's frame is up to code, it's time to make the house your home.
This isn't to say that once you've covered the basics of grammar, you never need to return or refer to them again. Find a homeowner who's never discovered a plumbing or electrical problem, or a leak or ding to deal with. In a similar way, there will always be another quirk to master in any language you study, including your native language, whether it's grammar or vocabulary. Language never stops evolving.
The point here is that once a good structure is built, maintenance is mariginal, as opposed to the bottomless pit of problems one encounters in living in a structure that's built poorly. Learning a language is like building a house: The more solid the foundation, the greater one's chances are for success and happiness.