Maybe I'm just not understanding the text that talks about it well enough but can someone please try to help me with Lenitions in Irish? I don't understand what they are for or when to use them properly. I need help.
When you first start learning, there's really three places you need to use lenition at.
The first one is for the past tense. When you put a verb into the past tense, you lenite it if it can be. If it's a vowel sound after it lenites, you put a d' in front of it. It stays on al the past tense verbs, even when you make them questions/negative, though the d' doesn't.
So, caith = 'throw'. Chaith = 'threw'. Fág' = leave, but d'fhág = left, ar fhág* -Did ___ leave? etc
The second is with a feminine noun. Feminine nouns that follow an take lenition, as do any adjectives which follow the feminine noun and are used attributively (so, in the sense of 'the red woman' v. 'the woman is red').
bean = a woman; an bhean = the woman; bean fhionn = a blonde woman; an bhean fhionn bheag = the small blonde woman, etc
The third ad final one is after the negative marker ní. When you use ní to make a verb negative. déanaim - I do/make; Ní dhéanaim - I don't do/make
I hope that helps, and please let me know if you've still got questions.
You would also need to use lenitions for "my", "your" and "his". eg. carr-mo charr, broga- do bhroga, briste- a bhriste. If the words start with a vowel, then "mo" turns to m', "do" turns to d' and "his" and "her" switch so that her apple = a húll and his apple = a úll.
Ok so I understand the first one and the third but how do you tell if a noun is feminine?
Apart from observing grammatical changes (e.g. bean → an bhean, so the lenition shows that bean is feminine; cailín → an cailín, so the lack of lenition shows that cailín is masculine), a dictionary will give a noun’s gender.
http://www.nualeargais.ie/foghlaim/nouns.php?teanga= This helped me a lot. Although it is far from perfect, I think you can guess some 85 to 90% of the genders if you follow these guidelines. The rest, of course, is dictionary.
Initial mutations (eclipsis and lenition, as well as various prefixes) are used in a whole range of circumstances, and for a variety of different reasons. Writing out a list of a hundred different circumstances that cause an initial mutation really isn't all that helpful for anyone (though you can find such lists, organized in different ways).
Lenition is indicated by placing the letter "h" after certain consonants, which changes the pronunciation of that consonant (the sound is lenited). Some examples of where lenition occurs are feminine nouns after the singular definite article ("an phéitseog"), verbs in the past ("bhuail sé") and certain other tenses, and nouns after singular possessive pronouns ("mo chóta"). Not all consonants can be lenited.
There really isn't much point in going into much more detail than that at this point - the best approach is to learn to recognize situations that might give rise to an initial mutation, and then start to remember which initial mutation occurs in that situation.