-이네요, -이예요 and -이에요 These are based on the special particle 이다, which equates two substantives like "am/are/is" in English. 이다 always does the coupling by attaching to the second noun at the end: "I am a student" -> 나는 햑생이다. To understand the phrases you asked about, you need to know the general sentence ending forms. There are many of them, but the common standard(plain statement), present tense forms are these four: 1 -ㅂ니다 (갑니다, 큽니다)) - formal, polite. (in formal speech, to people senior) 2 -(ㄴ/는)다 (간다, 크다)) - formal, plain. (in writing, occasionally in casual speech) 3 -(아/어)요 (가요, 커요) - informal, polite. (in daily speech, between adults) 4 -아/어 (가. 커) - informal, plain. (in daily speech, between friends or people very close) For 이다: 1. 이것이 첫방송입니다. (This is the first broadcast) 2. 이게 첫방송이다. 3. 이게 첫방송이에요 (이다 + 어 + 요 -> 이어요 -> 이에요) 4. 이게 첫방송이야. Thus 첫방송이에요 just means a "This is the first broadcast, without any special sentiment. -이네(요) on the other hand is one of the special ending forms that carry additional connotations. It expresses a mild surprise, like from a new discovery, and is said in a casual sense. So 첫방송이네요 (This is my first broadcast!) carries a special emotion from being on the first broadcast. -이예요 is wrong as an ending form, but you'll still encounter it. The reason is because of the following peculiar behavior of the -이에요 ending. 1. after a consonant-ending syllable, -이에요 must be used as is with no contraction(학생이에요). 2. after a vowel-ending syllable, 이에요 typically(almost always) contracts to 예요 (학교예요). So you see endings like 사람이에요, 친구예요, 책이에요, 기차예요, etc. We can say the only correct forms are -이에요 and -예요. But 이예요 is also seen because some nouns can end with 이. For example, a snail is called 달팽이, so we would say 이것은 달팽이예요. In this case, the ending structure is -예요 (#2 rule), but combined with the noun it ends up as 이예요. In other words, there is no recognized grammatical form -이예요, but it is seen pretty often by accident.

I'm not a native speaker, but I think I can handle this one. Let native speakers add to, or comment on my answer as well. 이 is derived from 이다, which is the sentence-ending part of a noun. Sometimes, it is described as turning the noun into a noun-verb. This is what combines with the other parts to answer your question. If the noun ends with a verb, then 이 is contracted with the 에요 to form 예요. For example, "I'm a doctor" would be "제가 의사예요." Since "의사" ends in a vowel, you can use "예요." In your case, the noun is 방송 which ends in a consonant. In this case, you need to use "이에요." So, "첫 방송이에요." The "이에요" and "예요" endings do not convey any kind of emotion or shade of meaning. You use them when it's just a simple statement, not necessarily introducing any new information into the conversation, nor any kind of exclamation or surprise, etc. (이)네요 conveys a mild surprise in your statement. I equate this to using "wow" at the beginning of an English sentence, or possibly adding on a "I was a bit surprised." Maybe you would just say "Really?" in English. Sometimes in English, we also do this with voice tone. As a native English speaker, I'm sure you can think of voice tone that conveys your surprise at something you're stating. This is the place when you would use (이)네요. So when I hear "첫 방송이네요," I would think of something like "Wow! It's the first broadcast," but I would hear that as implying "I wouldn't have guessed that since it was really good" or something like that. It just expresses a bit of surprise at the statement, and in this case, I would hear that surprise as being due to it being unexpectedly good for a first broadcast. Does that help/make sense?