Based on information I've gathered, Angelus would have what I shall term a "thin" Irish vocabulary, as opposed to a "thick" Irish vocabulary due to his education and status in the upper middle class. Therefore, his English would be more proper, unless he became upset, leading him to slip into a heavier brogue.

When writing "thin" Irish, the usage of the words "you", "your", and "you've" are proper.

When writing "thick" Irish, the words are replaced with "ye", "yer," and "ye've".

Other vocabulary changes when writing both "thin" and "thick" Irish:

English	Irish
of	o'
to	t'
not	no'
with	wit'
my	me
maybe/perhaps	mayhap(s)
nothing	naught
it is	'tis
it will	'twill
s/he is	s/he be
isn't	isna
wasn't	wasna
couldn't	couldna
shouldn't	shouldna
wouldn't	wouldna
didn't	didna
don't	dinna

If a word ends in "-ing" it changes to "-in'".

The use of the word "bloody" as an alternate for "damn" is the same as with the English.

Note: Angelus may speak Irish Gaelic, a language all its own.