As TESL, Should the English teacher explain the lessons in English or his/her native language for the beginner students to understand? and why?

without beat about the bush, the English teacher should explain the lesson in English even among the beginner students; in the meanwhile he should warm up the students and let them guess the  meaning. Every language has its rules and you can make any impact if you teach them by your (Mother Tongue) such as when you say a passage in a story  : " the next morning, at half past seven. she was standing in the garden" if you focus on the tone and the (n) sound you realize that the writer wanna deliver a message,the bell of a church (death) , which could be spoiled if you translate it to your native language. Furthermore,  I think this is the core point, focusing on meaning and thinking in the English language