Yes, Hamburg is countable, hamburger is a countable noun, and the plural form is Hamburg, which can be used with numerals or alotof(lotsof)manysome. Countable nouns refer to people or things that can be counted by numbers and divided into individuals; So it has a plural form, and when its plural form is used as the subject in a sentence, the predicate of the sentence also uses the plural form.

Nouns can be divided into countable nouns and uncountable nouns according to their countability. Countable nouns refer to nouns that can be divided into individuals and directly counted by numbers, such as desks, kites, girls, rooms, schools, etc.

Countable nouns are nouns that can be counted. Countable nouns have singular and plural forms. Such as: desktop computers, Apple computers, etc. Uncountable nouns are nouns that cannot be directly used for counting. Uncountable nouns have no plural form, only singular form. For example: some bread, milk, etc.

When singular countable nouns indicate general reference, they should be preceded by the indefinite article a(an), and when they indicate specific reference, they should be preceded by the definite article The; However, uncountable nouns cannot be modified by a(an). When expressing a specific meaning, the definite article the must be used in front.

The regular change of countable noun plural;

1. Add -s directly to the suffix of general nouns. For example:

Books → Library → Room.

House → House Day → Day.

2. Nouns ending in s, x, ch and sh, with -es at the end. For example:

Bus → Bus Box → Box.

Watch → watch plate → plate.

3. For nouns ending in "consonant letter +y", you should first change y into I, and then add -es. For example:

City → city subject → subject.

Factory → factory.