start working on some problem / task that's interesting to you. Every time you encounter some aspect of the language you don't understand, or aren't confident a

start working on some problem / task that's interesting to you. Every time you encounter some aspect of the language you don't understand, or aren't confident about, write a unit test for it that tests how you _think_ it behaves. If you're right, it will pass. if wrong it will fail. modify test until it passes. Then SAVE these tests as reference for how these parts of the language work while you're learning.