若果你是以中文翻译过来的,就必先要看你实在想表达甚麼了.
这里让我来弄清楚一下罢:
1 他爱在课室吃果西.(这是说他的一个习惯,即是常常都会这样做的,所以是现在式)
He likes to eat in the classrooms / He likes eating in the classrooms
2 他很常在课室吃东西.(这句跟上面同,而只是明确地可以鉴别出来是现在式而矣)
He often eats in the classrooms / He eats in the classrooms all the time.
3 他在课室吃果西.(这句可以意会到是一句陈述句,即事情已经过去)
He ate in the classroom (today / this morning)
希望可以帮到你.