@sullyfish6,
I live far from you. I know about verb tenses, I'm sorry. When I prepare my classes I pay attention to everything, but this text I wrote so quickly that I became worry about the way I put my thoughts, not about verbs, you know? I know, as teacher I must worry about everything relating to learning. The fact is, this episode I told here happened few days ago and I'm still in panic right now. I'm a fresh teacher then I decided to write in order to develop my performance. Now, after you read my text, I found many other errors. As you can see, it really works.
Anyway, if I'm wrong again you can correct me. I think you are an experienced teacher, aren't you?
Thanks for your help.