decide on
phr. v..phr. v.. to choose one thing or person from a group of options after thinking about it carefully.
phr. v.. to select a specific option or course of action from a range of possibilities; implies a period of deliberation prior to the final choice.
We need to decide on a color for the kitchen.
After looking at several different models, they finally decided on the blue sedan.
The committee spent three hours debating the budget before they could finally decide on a suitable candidate for the director position.
the object is usually the final choice made (a plan, a date, or a person).
contrast with 'decide to' (followed by an infinitive verb) versus 'decide on' (followed by a noun or gerund); 'on' emphasizes the selection process among alternatives.
We decided on go to Italy.We decided on going to Italy.the preposition 'on' must be followed by a noun or a gerund (-ing form), not a base verb.