Ha!
Someone in 1930s Ireland proficient in Irish could perhaps read 12th C Irish. Most people can't read Chaucer and struggle a little with Shakespeare.
Then in 1948 they fixed spelling to remove all the letters no longer pronounced, and some cases changed letters used. Modern Irish readers seriously struggle with pre 1948 Irish.
@ratsy I suspect you meant some Dialects of of Irish people speaking English!
Sons of Manannán Mac Lir:
Sgoith Gleigeil, the White Flower
Goitne Gorm-Shuileach, the Blue-eyed Spear
Sine Sindearg, of the Red Ring,
Donall Donn-Ruadh, of the Red-brown Hair.
(Not to be confused with Children of Lêr)
Gleigeil, Gorm-Shuileach, Sindearg and Donn-Ruadh we ignore. Those are typical colour referencing adjectives, not surnames. The English is given.
Just like lots of boy's names and unisex names in English are now only girls:
Sine = Sheena, a bloke.
Donall = Donal (easy).
My fluent Native Irish speaker hasn't a clue how Sgoith and Goitne is pronounced. She made some guesses.
More (simplified and inaccurate):
Conchobar (Old Irish pronunciation: [ˈkonxovar]; also spelled Conchobor, Conchobur; in Modern Irish: Conchobhar, Conchubhar, Conchúr : Actually it's quite close in Munster Irish to Connor.
Different regions of Irish have quite different pronunciation, so much so that though spelling in Ulster is the same, the pronunciation is often similar to radically different Scottish spelling (Gaelic, not English Scots dialect).
Lady Gregory and other old sources have Teamhair
But in Irish ph, th, dh, gh, mh are NEVER in separate syllables. For shorthand they used to put a dot above the letter instead of an "h"
So Teamhair is very approximately Tawera (as mh is sort of a w sound), it's called Tara now!
Since 1948, Irish doesn't work the same
http://www.smo.uhi.ac.uk/sengoidelc/donncha/labhairt.html
Disclaimer: I can't read / write or speak Irish at all. I'm rubbish at French pronunciation, my Irish pronunciation is far worse.