Articles

A
before a countable noun beginning with a consonant ( any letters other than a,e,i,o,u)


An
before a countable noun beginning with a vowel( a, e, i, o, u)

The

before a thing or a group of things which is the only one or only group that exists

before the names of seas, oceans, rivers, deserts, mountain ranges, buildings, hotels, theaters, restaurants, special means of transport, countries

before a superlative ( the highest degree of comparison of an adjective)
e.g. hottest, thinnest

before a particular noun or a noun that has already been mentioned


countries' names, the is used only when they are formed of more than one words or when they end in s
e.g. The United Kingdom, The Philippines


For names of cities, towns, districts, roads, streets, "the" is not used