When to use the definite article (the)

• 'r is used after a vowel,
  e.g. Mae'r coleg, o'r ysgol.


• yr is used in front of a vowel and h when the word in front ends with a consonant,
  e.g. yn yr ysgol, cyn yr haf.


• y is used in front of a consonant when the word in front ends with a consonant,
  e.g. yn y dref, cyn y gaeaf.