on the other hand
• used to introduce a contrasting point of view, fact, or situation.
• "Being a child star is bittersweet. On one hand, you're loved by millions, but on the other hand you're forever remembered for what you did years ago"
on the one hand
• used to introduce a point of view, fact, or situation, followed by another that typically contrasts with it.
• "On the one hand, I faced the prospect of losing my day-to-day contact with the kids. On the other, I faced sacrificing my career"
