There: referring to the existence of something

SINGULAR AGREEMENT	PLURAL AGREEMENT
There is occurs before a singular noun. There introduces the idea that something exists in an unspecified place.	There are occurs before a plural noun.
There is milk.	There are cookies.

SINGULAR AGREEMENT	PLURAL AGREEMENT
The verb following there commonly agrees with the closest noun even when there are multiple nouns or items. (British English differs.)	The verb following there may also be followed by a plural verb if there are multiple items.
There is a book, some pencils, and a notepad on my desk.	There are some pencils, a book and a notepad on my desk. (Eng-US)
	There are a book, some pencils, and a notepad on my desk. (Eng-Br; Eng-US formal usage)

SINGULAR AGREEMENT

PLURAL AGREEMENT

The verb following there commonly agrees with the closest noun even when there are multiple nouns or items. (British English differs.)

The verb following there may also be followed by a plural verb if there are multiple items.

verb agrees with plural items in list
There is a book, some pencils, and a notepad on my desk.

verb agrees with plural items in list
There are some pencils, a book and a notepad on my desk. (Eng-US)

There are a book, some pencils, and a notepad on my desk. (Eng-Br; Eng-US formal usage)

COMMON USAGE	MORE FORMAL USAGE
Nouns that are commonly paired together (salt & pepper, ham & eggs) often occur with singular verb agreement. (informal)	In formal usage, noun pairs occur with plural verb agreement.
There is milk and cookies on the table.	There are milk and cookies on the table.
There is bacon and eggs on the menu. (a dish; a menu item)	There are bacon and eggs on the plate.
There is salt and pepper on the plate. (regarded as a single unit)	There are milk and cookies on the table.

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