[an一般用于以元音音素开始的词前]
a university
一所大学
an honest man
一个老实人
A square has four sides.
正方形有四条边。
Rome was not built in a day.
罗马不是一天建成的。
twenty dollars a week
每周20美元
three times a day
一日三次
Brian is gifted in writing music; he is very likely to be a Beethoven.
布莱恩有作曲天赋,他很有可能成为又一个贝多芬。