Does Italian always use the infinitive where English uses the gerund?

Question

A phrase like "asking questions is a sign of a curious mind" is translated in Italian as fare domande è segno di una mente curiosa; the difference is clearly that English uses the gerund where Italian uses the infinitive.

Does Italian always use the infinitive where English uses the gerund?

The only case where this rule doesn't seem to apply is with giocando si impara, which is the translation of "you learn by playing." I would not say giocare si impara.
Is there any reason for using giocando in this case?

Answer 1

There is no “rule” such as the one you suggest. An English gerund might often correspond to an Italian noun (“running is a healthy sport” > “la corsa è uno sport salutare”), or some phrase not involving an infinitive (“seeing is believing” > “se lo vedi, ci credi”; you might say “vedere è credere”, but it would sound wooden and as a calque from English), and even an Italian gerund, as in the sentence you quote, which is not at all unique.

In general, in Italian a subordinate phrase with a gerund often expresses a cause, a hypothesis, a way of doing something (as in your example) and the like, so it may correspond to English gerunds introduced by “by”, “while” and so on. Say, “while returning from work, I saw...” > “tornando dal lavoro, ho visto...” but also “mentre tornavo dal lavoro ho visto...”

(Finally, “giocare si impara” is meaningless; if you were forced at gunpoint to use an infinitive you'd say something like “col giocare si impara”, but it would sound horrid.)

Answer 2

In giocando si impara, giocando is a ‘complemento di mezzo‘ or di ‘modo’; you would say, instead, giocare è divertente; on the other hand you'd say il bello del giocare è il divertimento (the good of playing is the fun).

The gerund has a meaning of cause, time, medium or mode. So for a specification you need the infinitive.

This is a cause of several errors when trying to translate Italian in English (or conversely): Questo è spesso causa di errori provando a tradurre l'italiano in inglese can have the gerund, because time is involved (quando si prova). But trying one's best in translating from Italian to English should be fare del proprio meglio traducendo dall'italiano all'inglese.