“Hanashi” is the root for the verb “hanasu” (話す、はなす), or “to talk”. Hanashi is “a” talk, more specifically. It is speech; it can also be taken as conversation, though we’d use “kaiwa” for conversation per se, and “soudan” for a discussion per se.
“Hanashi ga aru” can be read as “I have a talk (to have with you)“. In something that resembles English, this is very much like “We need to talk.” There’s an unspoken emphasis behind this; as in, we need to talk, now. You can also legitimately read this as “I need to talk to you.” In this case, there’s an implication of “to you, in private“.
The example that prompted me to write comes from the Valkyria Chronicles anime. I played the first game on PS3 in Japanese and loved it; the anime diverges quite a bit in places, some good things and some not, but it’s very pretty. One of the divergences is that the two main characters become part of a budding love triangle involving the leading male’s best friend going after the leading female.
After a lot of awkwardness, and the girl (Alicia) moping over it, she suddenly realizes that this is way too much thinking for her and she needs to make things clear. So, she storms over to the guy (Welkin), invading his office, and demanding a talk with him:
“Welkin!! Chotto hanashi ga aru n da kedo…”
The other words that modify and alter the tone of the phrase are as follows:
Chotto: This actually has kanji, though you’ll probably never see it in normal use; literally it’s a tenth of a small unit of measurement. In practice, it stands for “a bit” or “a little bit”. So a “chotto hanashi” is a wee little talk. This is slight verbal understatement (with a loud voice mind you).
N da: This is a softened version of “no da”, which would be a plain form of “no desu”. In other words, it’s a sort of middle point between really formal and really informal/ rude. It’s a pretty neutral in that sense.
Kedo: This is like a verbal ellipsis, like “ka” is a verbal question mark and “tte” is like verbal quotation marks. It’s a softener expressing something like “but”… <- just like these three dots. In other words, not literally “but” so much as making it come across less as an order. (Alicia is an NCO and Welkin is her officer, see.)
So, in toto, the most harmonized way to deal with it is “We need to have a little talk…” The grammar includes the three dots, but this would be very delicate to voice act with perfection. The bias would have to lean towards the strong tone. – J