This word came up in a multiple choice question, and was unexpectedly correct, and when I googled it, all the results seemed to be in Hebrew 8-o so I'm confused.
The sentences were:
Anyway, I don't need this.
בכל אופן, אני לא צריך את זה
בכל אופן, אינני צריך את זה
I'm thinking maybe it's some contraction of אני + לא? I don't know if I missed it in the tips and notes (if it is, if someone could point me to the right now that'd be brilliant...) or if it's an allowable translation that's been added without being explained.
אני לא - אינני
אתה לא - אינך Eincha
את לא - אינך Einech
הוא לא - איננו
היא לא - איננה
אנחנו - איננו but it almost never used
אתם / אתן לא - אינכם / אינכם
הם / הן לא - אינם / אינן
It's just another way to say the same. AdiDinar right - it's more formal way and will mostly be found in written literature or speeches. Usually in regular speech אינני would sound pretentious.
Finally there is also אנ'לא which is a shorthand for אני לא - it's very much informal, and it's based on the way people usually pronounce those world (i.e. it sound as one word). It's used mostly on Facebook posts, blogs etc.
You are correct. Both forms "אינו"' "איננו"are basically the same. Although
"אֵינֶנּוּ" is also used to express absence in third person: הוא איננו כאן – He is not here.
And also work in plural first person as in אנחנו איננו יודעים – We don’t know
That is not the case for the form אֵינוֹ
They are very much alike, but have some minor differences.
"Both world have the same meaning, as negation in third person. הוא אינוֹ יודע ≡ הוא איננוּ יודע.
The words we just created in different times.
In similar way the words איני≡אינני ואינה≡איננה have the same meaning, but originated from different times.
The word איננו has two distinct features: 1. The word used when you are talking about absence: you can say הוא איננו כאן, but it's not correct to say הוא אינו כאן. 2. The word איננו also used as negation form of first person plural (we) - אנחנו איננו יודעים.
It is the grammatical first person of the word אין, which stands for "there is no" or "none". So first person is אינני (i am not), second person is אינך (you are not) , third is איננו (he is not), etc. Note that in the first and third person it also comes in its shorter form of איני (i am not) and אינו (he is not).