If you don't do this
これをしなければ
You can't do this
これはできません
例えば、
If you don't pay money, you can't buy products.
お金を払わなければ商品は買えません
If you don't exercise, you can't lose weight.
運動しなければ痩せることはできません
ご参考になれば幸いです!
If you don't pay for this, you can't buy this product.
If you don't do some kind of exercise, you won't take off any pounds.
この場合、次のような言い方ができますよ。
ーIf you don't pay for this, you can't buy this product.
「お金を払わなければ、この商品は買えません」
to pay「代金を支払う」
ーIf you don't do some kind of exercise, you won't take off any pounds.
「なんらかの運動をしないと、体重は減らないですよ」
to take off 「体重を減らす」
ご参考まで!