Words Fail Me

A co-worker who works with me in convenient store had been living in China for about five years. He knows a little Chinese, but not very good at speaking. Any way he can understand me sometimes in Chinese. Both of us want to communicate with each other.
Firstly, we talk in Japanese, but my oral Japanese is not very good. So many times I can't make myself understood in Japanese. He advised me to use Chinese. I struggle to find the suitable and easy word to make him knew. But most of the time, it's a difficult job. Because I have to search for the easiest one, considering his Chinese level. As I am not a translator sometimes words miss me.

Liwen

Words fail me

Last time I had to present about me in YMCA speaking class. I prepared several words for this speaking. But when that time had come, I could not speak well. Usually I did not use like these words. I wanted to explain more and speak theoretically. The speech was not fine. Maybe the audience did not understand and they were tired to listen. That time I had to enrich my vocabulary and thinking.GC2 C15 F. Sasao

Words fail me

It was last year, I was working as assistant to native speaker for teaching kids from YMCA program in Summer.
My job was supporting teacher to make children understand and I worked for primary kids.
For me, it was difficult to order to students in English because I didn't have an experience growing by foreign environment. I can communicate adults because they have knowledge to understand what I'm trying to say. For children, I can say to them but some ways, I felt how can I say words in English. There were uncertain phrase in English and as well as in Japanese. So, which made me fail language.

Kae