Are you trying to learn a foreign language? So many of us try to do this with a "speed" mindset, always trying to rush things and force the process.
Books that promise "Spanish in 3 Weeks" don't help. There are even books on New Testament Greek that promise the "proven secret" to mastering the language in no time at all. The truth is, the "speed" mindset actually decreases the likelihood you'll ever be able to master the language you're trying to learn. If you're serious about learning a foreign language and maintaining it for the rest of your life, instead of trying to rush things and learn the language overnight, slow down and focus on the big picture. Aim for gradual progress and let those small improvements add up over time. I am currently trying to do this with my Spanish (which I tried to speak today at the Mexican place for lunch). Take your time. Focus on quality. In the end, taking a "slow and steady" approach is actually the fastest way to gain mastery of your subject.
I wish you well in your studies!