N4
なら
Were it, If, If it's the case, As for (Conditional)
田舎に住むのならば、車を買ったほうがいい。
If you are going to live in the countryside, it would be better to buy a car.
Explanation
「なら」 has 2 uses
1If that's the case
Picks up what someone said or the situation and gives advice or an opinion: 「日本へ行くなら、カメラを買いなさい」 if you're going to Japan, buy a camera.
田舎に住むのならば、車を買ったほうがいい。
If you are going to live in the countryside, it would be better to buy a car.
寒いのならば、ジャケットを着るといいだろう。
If it is cold, you should wear a jacket.
2As for
After a noun, narrows the topic to that person or thing: 「君ならできる」 you can do it, 「日本語のことなら先生に聞いて」 for Japanese, ask the teacher.
君なら、できる。
If it's you, you can do it.
デザートなら何でも食べられます。
If it is a dessert, I can eat anything.
Mixed up with
When the second action comes before the first, use 「なら」: 「駅へ行くなら、傘を持っていきなさい」 (If you're going to the station, take an umbrella).
When the second action comes after the first is done, use 「たら」: 「駅に着いたら、電話して」 (Call me when you get to the station).
Natural laws and sure results do not take 「なら」. Not 「×春になるなら、暖かくなる」 but 「春になると、暖かくなる」.