One of the more challenging things to master when you are learning Gaelic is the pronunciation. Gaelic has many individual sounds, and more than you can normally find in English, for instance. However, if you take note of a few key points, you should be able to learn both the pronunciation and the related spelling without too much trouble.
Key point #1 Gaelic sounds exist in pairs; this makes it important to learn the subtle spelling differences, so that you always recognise which is which;
Key point #2 In many cases, the differences between the sounds depend on whether consonants are made in a palatal or velar fashion.
Key point #3 In other cases, the differences depend on whether consonants are made in the alveolar area or between tongue and teeth.
Key point #4 Another crucial pairing in sounds is the difference between consonants that are unlenited and those that are lenited.
All of these points will be discussed below.
There are only 18 letters used to write Gaelic: five vowels and thirteen consonants. Of the thirteen consonants, only twelve are full ‘letters’, as such. The letter h behaves almost as if it was an accent or symbol. Its main job is to show sounds changes in the other consonants.
The five vowel letters represent roughly nine different vowel sounds in Gaelic. They do this by combining in various ways.
‘a’ is usually made with the mouth quite open and takes place near the back of the mouth. A similar sound can be heard in the word ‘back’ in the English of many native speaking communities. We can write it like this in IPA: [a].
‘e' has two main sounds in Gaelic: it can make the sound at the beginning of the name Eric, or it can be like the vowels sound in ‘lay’. In IPA, we write them as [ɛ] and [e].
‘i' normally represents the sound made with the mouth half-closed, lips unrounded and tongue fairly close to the roof of the mouth. When the vowel is short, it can sound rather like the ‘e' in ‘preamble'. It is written as [ɪ] in IPA.
‘o' represents two sounds, the ‘o' that is like the start of ‘otter', and the ‘o' of ‘over'. We write them as [ɔ] and [o] in IPA.
‘u' is like the vowel sound in ‘to' when it is short, but there is some dialect variation here. We would write it like this in IPA [u].
The other two main vowels are shown in the spelling by means of combinations of letters. To many beginners, these last two sound very alike. This is because they are both produced near the back of the mouth with unrounded lips. In fact, they are unrounded versions of two of the other, more familiar vowels.
‘ao' is pronounced like ‘u' but with the lips deliberately spread. A way to approximate it might be to say ‘u' for a few seconds and, while still saying it, spread your lips as if smiling. Of course, you will not be able to do this in the middle of conversation or when pronouncing actual words, but it may help you to get a feel for how to produce the sound. In IPA, we write it as [ɯ].
Although they may not look like a vowel, the two spellings adh- and -agh represent another sound with spread lips. This time, you can learn to make the sound by making an [o] and then spreading your lips as if trying to smile. In IPA, we write this one as [ɤ].
Gaelic is written with a surprisingly small number of consonants, considering the high number of sounds people make when speaking the language. This is permitted by the quite ingenious method established by the medieval scribes who wrote the common Gaelic language in marginal notes. They discovered that consonant sounds in Gaelic fall into groups of pairs and that it is easy to signal the distinctions between these pairs by using vowels as signals. Nowadays, we describe the groups of consonants as 'broad' and 'slender'. Broad consonants are the ones made with the mouth more open, generally with the sound further back. Slender consonants are made with the mouth somewhat more closed, generally with the sound made nearer the front of the mouth. Because the vowels can also be divided in the same way, we use vowel quality to signal consonant quality. Here is a simple example:
ca vs. ci
In the first combination, we have the broad vowel a. This tells us that the consonant beside it must also be a broad consonant. Thus, we know that we should pronounce it as a [k]. In the second combination, we have the slender vowel i. This tells us that it is beside a slender consonant, which we should pronounce with a palatal sound, [kj] or similar.