A dhialann dhil - - Dear diary

Bhí lá an-deas agam féin is ag mo dheirfiúr Orla inniú - -
I (myself) and my sister Orla had a very nice day today.

Note the word order. It is customary in Irish to put yourself first.

Bhí . . . agam - - I had ... . .
Bhí . . . ag Orla - - Orla had . . .
Bhí - - . . was (past tense of tá)

deirfiúr - - sister ; deartháir - - brother;

Go back to the possessive adjectives for a discussion of mo dheirfiúr - - my sister.

an-deas - - very nice; deas - - nice. You would expect a séimhiú on the d here but there is a rule which says that d, t, or s, are not lenited after d, n, t, l, s. It is called the "dentals" rule.
So an-mhór - - very big; an-bheag - - very small;
but an-dian - - very severe; an-te - - very warm.