Hi Chesda Mala Jupi Lyda Lynda and Kimlong,
Personally I think that there?s nothing causes confusions between Articles and Prepositions because they are quite different but it may do between the article THE and A/AN.
According to my knowledge about Articles :
A/An:They are used with singular, countable nouns:
1/ To refer to a thing or an idea for the first time. We don?t which person or which thing is.
Ex: We have a cat and a dog.
2/ We use a/an with professions/jobs.
Ex: Mr. Brett Angel is a dj.
3/ With some expressions of quantity/measurements.
Ex: a pair of...; a little of...; a few ...
4/ In exclamations with what + a count noun.
Ex: What a lovely day!
The:The is used with singular and plural countable and uncountable nouns.
1/ To refer to a thing or an idea for the second time or when both the speaker and the listener know which noun is being referred to.
Ex: We have a cat and a dog. The cat is black and the dog is white.
2/ When there is only one.
Ex: The world the moon the sun ...
3/ It is used before some formal names of countries, states and cities. (The ... of ...)
Ex: The United States of America, the Kingdom of Cambodia ...
4/ It is also used before some names of seas, rivers, ship, hotels, mountains and some more( I don?t remember all) :roll:
Ex: The Everest mountain, the Pacific ocean ...
5/ Before the ordinal numbers.
Ex: The first rank, the second floor ...
6/ With superlatives.
Ex: Who is the richest man the world?
7/ Before decades and centuries.
Ex: The 1930s, the twenty-first century ...
8/ When an adjective is used without a noun to present the class of people: the + adj.
Ex: The young and the old will both enjoy this movie.
9/ With names of people: the + plural surname can be used to mean <the ... family>
Ex: The Keos ===> Mr. and Mrs. Keo ( and children) ... :wink: :lol:
10/ Before names of musical instruments when we talk about playing them.
Ex: Can you play the piano, Somala?
There may be one or two more points about The and A/An and these are just what I can remember
Prasoeur