For example, the name "Ó Súilleabháin" is pronounced as "O'Shoo-il-eh-vawn". The apostrophe over the letter "S" indicates that the consonant is lenited, and it is pronounced as a soft "sh" sound rather than the hard "s" sound.
The apostrophe can also be used to indicate the elision (omission) of a vowel. For example, the name "Mac Dhubhghaill" is pronounced as "McDoo-il", with the apostrophe indicating that the vowel "a" has been omitted.
In some cases, the apostrophe may be used to indicate a change in the pronunciation of a consonant. For example, the name "Mac Mathúna" is pronounced as "McMa-hoo-na", with the apostrophe indicating that the consonant "th" is pronounced as a "h" sound.
The apostrophe is a crucial part of Irish orthography and pronunciation, and it helps to distinguish between different names and words in the Irish language.