Decide is a stand alone verb that is sometimes used with a following infinitive. "I've decided." "He decided to take the job." This can also be followed by an adjective clause. "I decided that I need a break." However, "decided on" is always followed by an object or clause. In this case, it means to choose something and not necessarily to make a decision. "He decided on where he wants to go for his vacation." "He decided on the red jacket, not the green one." Keep in mind that "decided on" and chose are not interchangeable. "He chose me," not "he decided on me." In this example, decided on is used in a nonstandard way. So, it's decided + 0, or decided + infinitive/adjective clause, and decided on + object (article + noun or clause) I hope this helps! Boa Sorte! Greg