① I'm not a bit tired, so I needn't have a rest.
② Tom's mother couldn't sleep well recently. She was not a little worried about Tom's health.
兩個詞組在加了not后，意思好像大不相同，請問這是怎么回事?
a bit 和 a little 在意思上非常相似，都表示“一點點，有點兒”之意。它們用作副詞，表達“程度”時，修飾動詞、形容詞、副詞、介詞短語或比較級，意思相同，可以互換。例如：
He is a bit like his father.
He is a little like his father.
他有點像他的父親。
The speaker spoke a bit louder in order to make himself heard more clearly.
The speaker spoke a little louder in order to make himself heard more clearly.
講話人把嗓門提高了一點兒，以便讓別人聽得更清楚。
但是，在下列情況下，它們是有區(qū)別的：
1. 當它們用作定語，表達“數(shù)量”時，a bit后要加of，a little 則不用。例如：
She ate a bit of bread for lunch.
She ate a little bread for lunch.
她午飯就吃了一點點面包。
2. 但是，一旦否定，not a bit 和 not a little的意思就大不一樣了，甚至相反。
not a bit 意思是“一點也不”，相當于not at all, not in the least之意。例如：
He is not a bit like his father.他一點也不像他父親。
Are you hungry? --- No, not a bit. 你餓了嗎? 不，一點也不餓。
She is not a bit happy.她很不開心。
not a little意思是“非常，很”，相當于 very (much), a lot 之意。例如：
He is not a little like his father.他很像他的父親。
I am not a little surprised at the news. 我對這個消息深感驚訝。
The boy was not a little worried because he hadn't heard from her parents for a long time. 那個男孩很擔心，因為好久沒收到父母的來信了。
【注意】有時bit之前，還可以加little，進一步修飾程度之低，如：
I'm a little bit tired. Let's take a short rest. 我稍有點累了。讓我們休息一會兒。
