Single Letter Words

Interesting single letter words to be found among the world's languages are the following:
"á" is Icelandic for river.
"å" (an a with a circle on top) is Swedish for river, stream.
"ø" or "ö" (an o with two dots on top) is Swedish for island.
"A", short from 'Aa', means big brother in Sudanese (West Java, Indonesia). To be used preceding a name, e.g. A Rudi - big brother Rudi.
"e" is Japanese for picture, bait or handle.
"e" (pron. uh) in Chinese means hungry.
"i" in Japanese can be stomach or well (the kind you draw water from).
"o" (long o) means large, big in Japanese.
"u" is Japanese for cormorant.
"u" (Burmese), a male over forty-five (literally uncle).
"i" (Latin) means ‘go!’.
"i" (Korean), a tooth.
"m" (Yakut, Siberia), a bear; or an ancestral spirit.
"Zi", short from "Zio", means uncle and informal an unrelated older acquaintance in Neapolitan dialect. It is used preceding a name, e.g. Zi' A' - Uncle Angel, Old Angel.

A famous Swedish tongue twister involving single letter words is the following:
"I åa ä e ö å i öa ä e å". (I ån är en ö och i ön är en å)
In the stream there is an island and in the island there is a stream.

And here is another interesting tongue twister in Bergamasco (Italian dialect):
"A o a ae, e öe i ae ie!".
I go and catch bees and I want them alive!

Two friends bet who would be able to write the shortest letter in Latin. Thus, the first man wrote: "Eo rus" -- ‘I am going to the countryside’. His friend responded with just a vowel: "I!" which means ‘Go!’... and had won the bet!

But, indubitably, the shortest written exchange ever was that between the French writer Victor Hugo and his publisher, following the publication of ‘Les Misérables’, with Hugo enquiring with a simple "?" about the book's success, and his publisher responding: "!".