[Grammar] There is/are

[angelene001]

I've got a huge problem with understanding when we use 'there is' and when 'there are'.
It's because of the influence of my native language.

1. There is a boy and a girl in the room.
There is a library and a post office in my town.

Are these sentences correct?

I thought that we use 'there is' + one countable noun in singular or an uncountable noun.
There is a boy.
There is milk.

And we use 'there are' + a countable noun in plural.
There are boys.

But what about the situation when we've got several countable nouns in singular:
There is a library, a post office and a park in my town.
Why not:
There are a library, a post officr and a park in my town.

2. And when we mix countable nouns with uncountable nouns?
There is milk, a cucumber, an apple and water in the fridge.
There are cucumbers, carrots and milk in the fridge.

I've always had in mind a rule that:
is+ one thing
are + several things

My car is ...
My car, my bike and my scooter are ...

Is it different with 'there is' and 'there are'?

Can someone help me with this problem?

 

[angelene001]

I'd be really grateful if anyone could help me at least partially with this problem.
For example with this part:

What about the situation when we've got several countable nouns in singular:
1.There is a library, a post office and a park in my town.
Why not:
2.There are a library, a post officr and a park in my town.

Is only 1 correct?

 

[Rover_KE]

Click here to find links to previous discussions of this topic.

 

[angelene001]

So the choice depends on the first noun.

But can a teacher mark it as a grammar mistake when I use "There are a library and a post office"?
I've found, searching through the posts, that it is acceptable. Some would say such a sentence.

 

[Rover_KE]

I would mark it wrong.

 

[5jj]

I wouldn't.