How consonants are pronounced depends on the vowels around them. i and e are "slender" vowels while a, o and u are "broad" vowels. This is quite consistent, there are very few exceptions. Gaeilge makes some sounds not found in English, so the best way to comprehend these is to listen to Gaeilge speakers.
Broad c:
k as in "kill"
Slender c:
ky as in "kyak" [ie "ceann" - kyawn]
slender b, f, g, m, n, and p all follow this pattern of a "y" sound sliding off.
Broad d:
d as in "door", same as English
Slender d:
makes more of a j sound [ie "deoch" - jukh]
Broad s:
s as in "salad", same as English
Slender s:
sh as in "shop"
Broad t:
t as in "tap", same as English
Slender t:
ch as in "chop"
Broad ch:
ch as in the Scottish "loch"
Slender ch:
ch as in the German "ich"
Broad gh:
Like ch in "loch" but with a g sound
Slender gh:
y as in "yellow"
Broad and slender dh:
same as broad and slender gh
Broad bh:
w as in "wall"
Slender bh:
v as in "van"
Broad and slender mh:
same as broad and slender bh
