It is a set structure: any form of "empezar" or "comenzar" + infinitive = +a.
Empecé a saltar, comencé a hablar, empezaban a correr, comenzara a escuchar.
It is the same with "terminar" or "acabar" + de + infinitive.
Terminaron de comer, acabando de cenar, termina de hablar, acababa de recoger.
In Spanish, many verbs must be followed by a preposition, which may or may not correspond to the preposition (if any) used in English. check the links:
a + infinitive
a + object
When an action is in progress, you can use a verb that shows the continuation (seguir, continuar) plus the present participle (-ing words in English): continuar caminando, seguir caminando
You can´t use the same construction with ¨empezar¨ because you either start, or you do not. I do believe you can say ¨continuar a caminar,¨ but "continuar caminando" is the preferred construction.
In Spanish the particle like "a" between 2 verbs is linked to the first one. Here, 'empezar a' 'to begin TO' then 'to' translated 'to' from the following infinitive is voided, but if you're a native speaker of English, it should still make sense if you think about it as "to begin to to walk".
I find this a little confusing. DL gives me the thumbs up for "I am going to begin to walk." and then gives "I am going to start walking." as 'another correct solution.' Is there a difference? Are they interchangeable? I thought the phrasal future was "conjugation of 'ir' + a + infinitive." "To walk" is the infinitive, not "walking," yes?
You have a lot going on in your short post. :) You are right that the phrasal future is "conjugation of 'ir' + a + infinitive" ,so voy a empezar = I am going to start
For the last part of your comment, there are many situations where in English we use the "-ing" form of a verb but in Spanish the infinitive would be used. So, the Spanish infinitive is sometimes the English infinitive and sometimes the Englsih gerund (-ing form).
In English, in some verb combinations the second verb must be an infinitive while in other situations the second verb will usually be a gerund.
In Spanish the second verb would most likely be an infinitive.
Many thanks! I think part of the confusion for me is that DL's "gerund" unit isn't actually about gerunds at all. It sent me off on the wrong path and I had to sort of back up and straighten out the English gerund and the Spanish gerundio -- and then rethink the use of the infinitive as a gerund in Spanish. You gave some good links, thank you!