It used to be quite normal for parents to let their kids go out and play without really watching them very much.
Parents never used to watch their kids when they went out to play the way they do nowadays.
ーIt used to be quite normal for parents to let their kids go out and play without really watching them very much.
「昔は親が子供達をちゃんと見守らないで外で遊ばせるのは全く普通だった」
to let one's kids go out and play で「外で遊ばせる」
to watch で「注意して見守る」
ーParents never used to watch their kids when they went out to play the way they do nowadays.
「昔は今と違い、親は子供たちが外に遊びに行く時見守ることをしなかった」
to go out to play で「外に遊びに行く」
nowadays で「近頃・現今」
ご参考まで！
カナダ 
