1. In our country, a memorable day is set according to a special date. However in America a memorable day is set according to the ordinal day of a special month.

2. When you write a letter, there is a set form. It begins with a greeting like 'Dear Mrs. Johnson.' After you write a body you close the letter with a closing word such as 'Yours truly.'

Are both grammatical?

#1 = You could put a comma (,) after However in the 2nd sentence.

#2 = You could put a comma after "After y ou write a body," if you wished.

Yes, both statements are grammatically correct.

1. In the first statement, the use of "according to" indicates that the memorable day in each country is determined based on different criteria. In one country, it is set according to a special date, while in America, it is set according to the ordinal day of a special month.

2. The second statement describes the common format and structure of letter writing. It states that a letter usually begins with a greeting, such as "Dear Mrs. Johnson," and ends with a closing word or phrase, such as "Yours truly." This format is widely accepted and considered grammatically correct in English letter writing conventions.