Simply put: Tudo: everything Todo/toda/todos/todas: all Tudo: Eu tenho tudo que preciso. I have everything I need. Todo/toda/todos/todas : Eu tenho todo tempo no mundo. I have all the time in the world. Ele comeu toda a comida. He ate all the food. Todas as flores são cheirosas. All the flowers are fragant. Todos os leões são carnívoros. All the lions are carnivore. Sometimes "todo" can mean "any", or "every". It depends on the context. The same question was asked here on Italki few years ago. There are more examples. Check it out: http://www.italki.com/question/36385 The answers were pretty useful. =] Hope that helps.

Todo: all; everybody; everyone (todo mundo/todos) Tudo: everything