Because it depends whether it is a vowel or a consonant. For example 'a apple' is wrong. 'an apple' is correct. 'a book' is correct. 'an book' is wrong. The word that begins with a vowel like orange,...
"Christmas Trees" have a long history that predates the birth of Christ. In ancient times evergreen trees were used to decorate homes for celebration of winter feasts. Martin Luther is said to have...