para aprender a ser

Question

The phrase "para aprender a ser" is the "a" an idiomatic expression? is two consecutive infinitives incorrect?

Answer

Hola Lorie
it is indeed possible to have two infinitives together, for example:

Poder salir a la calle en estos momentos es esencial.
(Being able to go out to the streets at this moment is essential.)
Ella quiere intentar ayudar a su hija.
(She wants to try to help her daughter.)

Depending on the verb, they can be immediately followed by another infinitive.
In this sentence from the dictation:

Yo estaba haciendo prácticas en un colegio de Méjico
para aprender a ser profesor.

The verb aprender is always followed by the preposition "a" (to learn to do something)
It'd be incorrect to omit the "a" here:
"...para aprender ser profesor" 
Saludos
Inma