Key Points of Beginner Japanese Grammar!

Is it difficult to use "~nikui" and "~yasui" properly?
Hello! My name is Kubo, and I am a teacher at TCJ.
In this article, I will introduce common grammar mistakes learners of Japanese language often make.
I would like to teach some Japanese grammar as much as possible to help learners of Japanese language!
wakarinikui (わかりにくい)
I often ask my students who are non-native-Kanji-readers such as Europeans, Americans, Indians, "How are your Japanese studies going?”
One of my students answered "Kanji ga wakarinikui (It is difficult to understand Kanji), Kanji ga takusan arimasukara (because, there are many Kanji in Japan).
When I just started teaching Japanese, I thought, "Hmm? wakarinikui?, grammatically something is wrong.”

What should he say correctly in this situation?

The verb + nikui means difficult to do.

What does the "difficult" mean exactly?
You can use wakarinikui to tell your intentions.
For example,
He is not very good at talking and it is difficult to understand.
The map he drew badly is difficult to understand.
This sentence is poorly constructed and difficult to understand.

In other words, it is because the way of doing things is not the right way, so "wakarinikui" = "I don't understand".
If the reason is that there are a lot of kanji, the answer is kanji ga yoku wakaranai.

kanji ga wakarinikui sounds like the person who created the kanji at the very beginning should have made reading these easier but they did not. I know kanji is difficult, but complaining about them doesn't help.
wakariyasui (わかりやすい)
When I ask my students, "How is class today? ", they sometimes answered, "wakariyasuidesu" (It is easy to understand, because I prepared for today’s lesson before).
I also felt that their way of saying it was weird and that something was wrong.

Verb + yasui means easy to do.
wakariyasui (easy to understand) is not because of your own efforts, but because someone else's way of doing is good.

If the reason you understood the lesson is that you made an effort (i.e., you prepared for lessons properly), you need to say, "yoku wakarimashita" .

I feel great if my students say, " Your explanation was very good today, so wakariyasukatta desu! “. However, they usually don’t say it...

The grammar of verb + nikui/yasui is not difficult in terms of meaning, therefore the students who study Japanese usually use this grammar when they explain something. However, most of them use this grammar in a wrong way as described above and its usage is well-established for them.

Therefore, I often tell my students, “Please do not use nikui , because it is difficult to use”. Japanese learners should use the basic grammar of "yoku wakaranai" and "yoku wakatta" instead of using nikui and yasui.
tabenikui (たべにくい)
By the way, I looked up pictures of "tabenikui okashi (hard-to-eat sweets)" in preparation for lessons, which teach verb + nikui/yasui.

Which sweets are hard to eat?
For example, sweets that are crumbly, and sweets that are too big to eat.
When I looked up images featuring the word, I found many pictures of swiss rolls which are the specialty of Hokkaido.
However, all pictures are just normal swiss rolls. It did not seem any more tabenikui (hard to eat) than a normal one either. Why is it so tabenikui?

After I did some research on it, I found out that the swiss rolls are very sweet and that the manufacturer that makes it advertises with the slogan: Our swiss rolls are the hardest to eat (tabenikui) in Japan, but it is delicious when you try it.

Are these swiss rolls really sweet and hard to eat?
I would like to get my hands on one of these swiss rolls, and find out whether they really are tabenikui (hard to eat) or just oishikunai (not delicious).

However, I can not eat anything too sweet (taberarenai), so I may not be able to find out whether this cake is really hard to eat (tabenikui).
& DM