"Tapadh leat a bhalaich!"
Translation:Thank you, boy!
"Bhalaich" is the lenited form of "balach". Feel free to take a look at the duolingo wiki: https://duolingo.fandom.com/wiki/Scottish_Gaelic_Skill:Phrases
So in bhalaich (correct me if wrong) I think the 'h' comes from lenition because of the 'a' (since we are addressing the person) but I'm confused where the 'i' comes from? I know in Irish this is often used to pluralise, but we are talking about a singular boy right?
EDIT: I'm going to answer my own question cause I figured it out. It turns out that when using the vocative case you ALSO slenderise masculine nouns (i.e. you make the final consonant slender by using a slender vowel (i, e) in addition to lenition
No. the 'a' indicates that you are speaking to him rather than speaking about him. It's a distinction that's not made in English. In a language that does distinguish, to neglect it will sound wrong, kinda like if in English you use someone's name where "you" would normally be said instead.