Long
い adjective
This is a single kanji with an い on the end, meaning you know it's probably an adjective. What's the adjective form of long? It's also long.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
You have something that's really long. It's this crazy hair growing out of the tip of your nose. You don't really care either way if it stays or goes, but you're too lazy to cut it off. Your parents, though, keep trying to nag (なが) you to trim it. Imagine this process happening and be irritated about it. What naggers.
はなしが長い
story is long, talk is long
毛が長い
hair is long
ツメが長い
nails are long
長いあいだ
a long interval of time
長い人生
long life
長い年月
many years
先は長い
long road ahead
十年は長い
ten years is long
人生は長い
life is long
かなり長い
considerably long
少し長い
little long
とても長い
very long
この川は長いです。
This river is long.
子犬にとって、一年はとても長いです。
One year is very long for puppies.
このエピソードは長すぎる。
This episode is too long.