Learning a foreign language by speaking is more important than just learning grammar rules. Your most important goal is to make an effort to speak even with the least knowledge of English. One of the most basic sentences while learning Turkish in primary education is "Ali, take the ball". We are expected to say this sentence out loud. Our ears are expected to hear this sentence with our own voice. As the ear hears with our own voice, we become ready to speak. We need more vocabulary to develop by hearing with our own voice.
The essential rule when speaking a foreign language is to improve our vocabulary regularly. We cannot form sentences without knowing the words. Even if we know the grammar and can speak, we cannot continue speaking without words. When improving English, the goal should be to both speak and learn new words. It is important to learn words not by memorizing, but by placing them in permanent memory. Our speech can be fluent when words are permanently embedded in our memory. Even if speaking practice is not done with the correct grammar rule, English speaking skill can be improved with vocabulary.
To learn English grammar, you can progress quickly when you open a grammar book and start learning. As you learn fast, you can think about how quickly you improve, increase the hours of English study and learn the main grammar rules in a short time. But that doesn't mean you can speak English. This does not mean that you will understand when you listen to something, or that you can write what you listen to.