区别如下：
一般过去时：
概念：过去某个时间里发生的动作或状态；过去习惯性、经常性的动作、行为.
时间状语：ago, yesterday, the day before yesterday, last week(year, night, month…), in 1989, just now, at the age of 5, one day, long long ago, once upon a time等。
基本结构：①be动词；②行为动词
否定形式：①was/were+not;②在行为动词前加didn't,同时还原行为动词.
例如：
I was student ago. （be动词过去式）
I bought the book yesterday.（行为动词buy过去式）
I didn't buy the book yesterday. （行为动词否定形式）
现在进行时：
概念：表示现阶段或说话时正在进行的动作及行为.
时间状语：now, at this time, these days等。
基本结构：am/is/are+doing
否定形式：am/is/are+not+doing
例句：
I am doing my homework now.（be+动词的ing）
He is not watching TV now.（be动词的否定形式）
一般现在时：
概念：经常、反复发生的动作或行为及现在的某种状况.
时间状语：
always, usually, often, sometimes, every week (day, year, month…), once a week, on Sundays, 等。
基本结构：①be动词；②行为动词
否定形式：①am/is/are+not;②此时态的谓语动词若为行为动词,则在其前加don't,如主语为第三人称单数,则用doesn't,同时还原行为动词.
例句：
I always go to library every week.（行为动词）
He often don't brush teeth.（行为动词的否定形式）
一般将来时：
概念：表示将要发生的动作或存在的状态及打算、计划或准备做某事.
时间状语：tomorrow, next day(week, month, year…),soon, in a few minutes, by…,the day after tomorrow, 等。
基本结构：①am/is/are/going to + do；②will/shall + do.
例句：
He is going to read many book next week.（be动词+going to do）
We shall visit the Great Wall next Sunday.
如有疑问，请追问，满意，请采纳，谢谢！