"I am Angus."
Translation:Is mise Aonghas.
Your thanks are appreciated, but since you are thanking me for explaining the vocative, you could say a DhaibhidhR. Of course the last vowel would slenderize since it is a masculine singular noun - except that is slender already. This is actually quite unusual in Gaelic. The vast majority of Indo-European masculine singular nouns and names end in a broad vowel. The reason this one does not fit the rule is that it is not an indigenous name - it is Hebrew. It comes from Biblical Hebrew דּוד (Dāwîḏ, literally “beloved”). Obviously Hebrew does not follow Indo-European rules on what vowels names should end with. In fact it is more extreme than that. Vowel aren't very important in Hebrew at all (except for inflections). That's why it is spelt with only three letters - DWD. The dot was added later to give a bit of a clue about the first vowel. You will find that almost all Hebrew words that aren't compounds have three consonants, with no one caring much about the vowels.
There are two verbs for "to be" in the Gaelic. "bi" which becomes tha, chan eil, a bheil, etc is used to describe something/someone eg tha i fuar-it is cold or tha e àrd-he is tall. "is" is used to define something/someone is mise Aonghas-I am Angus or 's e nurs a th' annam-I am a nurse.