I really can't understand the difference. As far as I understand it, 出会い is a noun and 出会う is the verb. But I can't get my head around how to use them in a sentence!
Too add to the confusion, when I used tangorin to search for 出会い example sentences this was one of the examples:
わたしは素敵{すてき}な人{ひと}たちと出会{であ}いました。
Surely it functions as a verb in this case?
Also, when is it appropriate to use 出会う instead of using 会う?
Thank you!
[出]{で}[会]{あ}う is a verb that means to come across or in some contexts to meet (but not in the sense of "have a meeting with"). Thus it's basic meaning is to chance upon something.
[出]{で}[会]{あ}い is two things -- and it's not a coincidence.
[出]{で}[会]{あ}い is what is often-called the "masu-stem" in English or 連用形 in Japanese. This is a productive form which for 五段 / type i verbs like those that end in う changes to い. (For 一段 / type II verbs, the final sounds disappears -- 食べる -> 食べ)
Thus, one use is when you join 出会う to the helping verb ます to make it more polite. = 出会い + ます = 出会います
The other thing that happens is that for many verbs the masu-stem / 連用形 has become a noun as well with a meaning like an -ing noun in English.
So 出会い can also mean "meeting" (under the meaning to chance upon something or encounter it).
Similar production can be seen elsewhere:
遊ぶ -> 遊び
話す -> 話し
飲む -> 飲み
食べる -> 食べ
切る -> 切り
My sense is that this not universally productive (meaning I don't think every single verbs' 連用形 will be a known and usuable noun).
「出会う」 is the dictionary form. To use it in a sentence, you need to change the form accordingly. In this case, we change it to the "masu" form. "u" sounds at the end of dictionary forms often change to "i" sounds when doing so.
帰る：帰ります
買う：買います
出会う：出会います
When changing dictionary forms in to nouns, you follow the same rules, but by adding 「ます」 at the end it becomes a polite way of saying the verb.
There's actually a deeper history behind the grammatical use of the "masu" form which would explain this situation, but you don't need to know that now. Too much information. Please feel free to google it later on though, the history of the Japanese language is fascinating!
出会う vs 会う is rather simple. 出会う implies that the meeting is a coincidence, whereas 会う implies the meeting was planned.
