I've been learning Japanese for about 4 years now, and I notice that as time passes, I have to change my study habits more often. When I first started studying, super casually, I learned about one word a week and could only make basic sentences. 

I took a relaxed approach to language learning and didn't rush. On my third year of Japanese study, I started to really take things seriously and study intensively. I did tons of flashcards and kept several notebooks. I couldn't learn from the same methods I used in the beginning, mostly because I changed intensity. 

As I continued learning at an Intermediate level, I found I hit a ton of roadblocks. Suddenly, flashcards didn't work anymore. I couldn't absorb new grammar. In language learning, what was effective in the beginning, tend to grow ineffective as time passes. I believe this is true for any language, not just Japanese.

In the beginning, I absorbed information like a sponge. I learned new vocabulary quickly, and it all stayed in my head. However, as I hit the Intermediate line, a wall came up. Suddenly, I couldn't learn vocabulary or grammar, no matter how much I studied.

This is what's called the 'Intermediate Plateau'.

When you hit the Intermediate Plateau, you might be tempted to walk away for a while and come back later. Try not to.

The best thing to do with any subject is to delve into a part of the subject you haven't explored much, and to give that your full attention.

After being stuck on the plateau for a while, I decided to start looking at kanji, since I had been largely ignoring that aspect of Japanese. I created a Kanji "journal" where I studied 10 kanji a week. I ended up learning a lot of Kanji for the 2 months I did that, and gradually I incorporated new vocabulary into my study regime.
Since I came from a background of little to no Kanji, suddenly beginning a new aspect of language learning made my brain react as if I was learning something entirely new. I absorbed new Kanji like a sponge and was able to focus on this for a short period of time but experience rapid progress.

I slowly began to incorporate things I used to study, such as grammar and vocabulary, into my regime while keeping Kanji study as the main activity. As I hit my Kanji goal for this intense study regime, I gradually weaned off Kanji and headed back to studying vocabulary and grammar full time.

When you pay attention to an aspect of a certain subject you haven't been doing, it allows you to refresh your brain and focus on something entirely different. It's sort of like giving your brain a 'breather'!

Another tip for those stuck in a language learning plateau: don't be afraid to explore other methods of studying, as that may be a big part of the problem. If you're someone who learns visually, explore methods that require meticulous note-taking. If you're someone who learns best by copying something over and over, try using what you're learning in your everyday speech as much as possible. Approaching the same problem from a different perspective can make it seem as if you're attempting a new task, which can up your motivation and attentiveness!

All in all, especially in language learning, the Intermediate Plateau is inevitable. 

Getting through this is possible with enough hard work, though it may be discouraging to notice your progress slow as you advance. Despite this, keep going! The fact that you've reached the plateau in itself is a sign you've accomplished a lot, and are capable of a lot more 💕