[mikekchar]

Your advice is common amongst educators these days, but the general consensus in language acquisition research is completely the opposite. If you can understand something, with enough repetition, you will acquire it. Free reading of native material is hands down the most effective way to acquire a second language that we know about.

There are quite a lot of scholarly works accessible from the internet on the topic, so if you are interested I recommend taking a look. I was going to link some examples, but it's probably better for you to find your own way without my biases.