Some 和 a lot of 用法上有什麼分別?

Some

a.[Z]
1. (修飾名詞的單數形)某一,某個
She is playing chess with some boy.
她在和一個男孩下棋。
2. (修飾名詞的複數形或不可數名詞)某些,若干,一部分的,一些
I have some work to do this evening.
今晚我有些事要做。
Some mushrooms are poisonous.
有些蘑菇是有毒的。
3. 好些,好幾個,不少
He lived in London for some years.
他在倫敦住了好幾年。
4. 【口】了不起的,驚人的
5. 【口】不怎麼的

pron.
1. 一些,若干
Some of the students are from the North.
有些學生是北方人。
Some of the meat has gone bad.
一些肉已經壞了。
2. 有些人,有些事物
Some smoke and some don't.
有些人吸煙,有些人不吸。
3. 【美】【口】許多,大量

ad.
1. 【口】稍稍,有幾分
His mastery of the language has improved some.
他對該語言的掌握有所提高。
2. 【口】很,非常
I felt worried some.
我愁得要命。
3. (與數字連用)約,約莫
Some twenty passengers were killed in the road accident.
這次交通事故中約有二十名旅客死亡。

A Lot of

ph.
1. 許多