It depends on how many times we derive and generate words from our brain to improve non-mother tongue. This applies to not only English but also any languages. When it comes to output, overwhelming number of times is more important than the quantity. This process creates the new nerves in our brain and makes the drawer move smoothy.
For example, even if you are not good at controlling chopsticks now, you will be able to use them by keeping practicing . You also will be able to use it wth your left hand skillfully. Keep giving stimulations to our nerves is quite indispensable.
To generate tremendous number of outputs, it’s necessary to get a great number of inputting. When it comes to English (non-core language), as my opinion, being able to outputting actually will be more or less 2-3out of 10, the amount of inputting. Therefore, increasing the amount of inputting drastically is required.
When it comes to listing, external stimulations will reinforce the nerves. We should have a shower of stimulators such as TV, radio, movies and have discussions with others.
Overall, the number of times is more important than quality in building nerves of languages.