"The leaves begin to fall."
Translation:As folhas começam a cair.
The verb "começar" usually requires the preposition A when something "start/begin TO". Começo a trabalhar às oito = I start work at eight.
When it means "in order to" it applies: "vamos começar para não atrasarmos?"
In situations like these where the infinitive verb is preceeded by a prep due to the preps association with the previous verb, why do we use the infinitive at all? Couldn't we just use "cai" here?
I'd say when you have a verb after "começar", it should be "começar a", and not "iniciar". I don't exactly know whether this is wrong, but a native spaker wouldn't use it.