In addition to the previously mentioned, I also noticed this correction:

What I think the most difficult part of ITALKI lessons is!

I had my first italki lesson in early May and had been getting along with different italki teachers for 2 months. I found my English learning had reached a plateau, and the most difficult part of it can be "finding appropriate topics with matched teacher."

When it comes to language learning, the language itself can be the least important part. Language is just a tool for human, and it's even still just a tool in the process of language learning. The core is the comparison and communication of different cultures, that is to say, the world views of two groups of people. Anyway, language is a culture thing.

Notice the fact—— even with your best friend, you can never always come up with attractive topics at any specific time, let alone the stranger on the other end of the network who <s>have</s> has cultural barriers with you.

The ultimate core of italki learning: "finding appropriate topics so both teachers and students getting involved and having fun" needs efforts, honesty, and sincereness from both sides.