English is used to describe numbers in ordinal form, such as: No.65438 +0 first, No.2 second, No.3 third. Except No.65438 +0 ~ 3, all numbers are marked with TH: No.5 ~ No.365438+0: No.5 ~ No.31.

Ordinal numbers can be used as subject, object, attribute and predicative in sentences.

Example: the second one is what I really need ..

The second one is what I really need. (as subject)

Without this case.

In English, ordinal numbers should be preceded by the definite article the, but not in the following cases:

1. When the ordinal number is preceded by an adjective subject pronoun or a noun possessive case, it is not.

2. When expressing fractions, ordinal numbers do not use before.

3. When expressing "another, another", the ordinal number is not before, but an indefinite article can be added.

4. When expressing "year, month and day", the ordinal number does not use before.