take (one) out to dinner
To bring or accompany one to or meet one at a restaurant to eat dinner together and pay for the meal, often but not always as a date. I saw you from across the bar, and I was wondering if I could take you out to dinner some time. The boss is taking us out to dinner to celebrate the deal.
take someone out to dinner
to take someone as one's guest to a meal at a restaurant. Can I take you out to dinner sometime? We will take out the visitors to dinner tonight.