1.英语中什么情况下可以不使用冠词和数词?2.go to bed是惯用的短语可是我看到的对话where go go to

1.英语中什么情况下可以不使用冠词和数词?2.go to bed是惯用的短语可是我看到的对话where go go to hospital.这两个句子有错误吗?3.使用冠词跟不使用冠词有什么区别?

不加冠词的基本规则
1. 季节、月份、日期、节假日前一般不加冠词.
If winter comes can spring be far behind? 10.1 is National Day.
2.表示球类、棋类、三顿饭的名词前通常不加冠词,但乐器前需加定冠词.
What did you have for lunch? Dinner is ready. Let's go and watch them play chess. My elder brother likes to play football. The boys are learnig to play the guitar.
play the piano play the violin
3.有些固定词组中的名词前不加冠词.
at noon at night at dawn at midnight in the morning
in the afternoon in the evening in the daytime in town
in front of （at the back of） at distance （in the distance）
as a whole on the whole to catch cold to have a cold
1、冠词修饰名词.
Please go _____ upstairs after you have finished the lunch.
upstairs是副词,前面不需要加冠词.
2、可数名词单数泛指,前面加不定冠词.an用于读音以元音开头的单词前.
Reading English story books is a good way of improving your English.
I have been waiting for him for half an hour.
3、名词特指时,前面加定冠词.
He is enjoying his stay in Denmark, but has some difficulty with the language.
Is the water from the tap fit for drink?
4、可数名词的复数和不可数名词泛指,前面不加冠词；大部分专有名词前也不加冠词.
As we know, the most dangerous enemies are those who pretend to be friends.
They left for work after supper.
The film includes some recently discovered newsreels of World War II. （the Second World War）
5、冠词在固定词组中的特定用法.
Without any news from Tom for a long time, his father left for Shanghai to see him.
They will travel by air.
I will help you for the sake of your sister.（for the sake of 因为）
I will go to school on foot.
My mother is in hospital.
He has been in prison for two years.