When learning a language, people tend to progress in bursts. This means that there will be times that you feel like you are really learning fast and other times when you seem to plateau. The reason for this plateau is not quite clear although I would like to suggest a couple of theories and ways to combat this and take your English level higher.
Loss of motivation
Motivation will come and go and if you want to keep it longer, you have to find ways to motivate yourself. Motivation is usually a combination of your emotional state, your feelings toward the teacher or class, your stress from studying and other activities, pressure from family and friends and the goals that you set yourself and how you feel about them.
The easiest way to break out of a motivational slump is to set yourself a few short, easy goals. A couple of easy wins will help you to feel confident and willing again.
If that doesn’t work, try finding the source. If you are losing motivation because of stress or your relationship with a family member or your teacher, then that is the challenge you need to face to get your motivation back.
You need time to absorb
Sometimes, if you study at a quick pace, you need to just step back a little and spend some time practicing what you have already learnt. A lot of times, students study the grammar to an advanced level but they have not spent the time practicing the language that they have learnt. So they feel that they are not progressing.
In this case, the best thing to do is to start with the basics and practice. Remember, the stronger you build the foundation, the taller you can build the tower. This is especially true of English. Practice and work grammars that you have already studied into your regular vocabulary and you will be ready to take your English to the next level.