Learn Spanish (Latin America): En el bosque, el ermitaño solía hablar solo y se volvió excéntrico. - In the forest, the hermit used to talk to himself and became eccentric.

We use volverse to talk about involuntary or deep changes in someone's personality, behavior, or character. Because becoming eccentric (excéntrico) is a psychological shift rather than a deliberate career choice, volverse is the perfect fit. If he had deliberately become a monk, we would use se hizo.

How does solía hablar translate to 'used to talk'?

The verb soler means to be in the habit of doing something. When used in the imperfect tense like solía, it is the most natural way to say 'used to' do something in the past. It is always followed directly by an infinitive verb, which is hablar in this sentence.

Why does the sentence use hablar solo to mean 'talk to himself' instead of hablar a sí mismo?

While hablar a sí mismo is understood, hablar solo (literally 'to talk alone') is the most common idiom for talking to yourself in everyday Spanish. Remember that solo acts as an adjective here matching the subject, so a female hermit would hablar sola.

Why does this sentence mix the imperfect tense (solía) and the preterite tense (se volvió)?