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.
当然考える
a natural consideration, would naturally think about something
当然ある
something is naturally there, of course there is something
当然知っている
common sense, of course one knows 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.