Natural
Obvious
な adjective, の adjective
Something that's naturally right is something that's very obvious and natural. You know that, right? 当然!
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
当然知っている
common sense, of course one knows something
当然ある
something is naturally there, of course there is something
当然考える
a natural consideration, would naturally think about something
「すごい！あのテストで百点とったの？」「当然さ。」
"Wow! You scored a one hundred on that test?" "Naturally."
日本語が上手くなりたいのなら、毎日少しずつでも練習するのは当然でしょう！
If you want to become proficient in Japanese, it's only natural to practice even just a little every day, right?
あんな良い彼女がいるなんて、お前は本当に運がいいよな。当然のことだなんて思うなよ。
You are very lucky to have such a nice girlfriend. Don’t take her for granted.