notadictionary.com
a veces las personas mas calladas son las que menos hablan
→ “Sometimes the quietest people are the ones who talk the least.”
a — at, to, or by (here it's part of a common phrase structure)
veces [times] — times, occasions — literally 'times' but used for 'sometimes'
las personas [rén wù] — people — literally 'persons' but used for 'people'
mas [más] — more — here it means 'most' in a superlative sense
calladas [qiǎo jìng de] — quiet — literally 'silent' but used for 'quiet' in this context
son [shì] — are — linking verb, equivalent to 'to be'
las que — that/who — relative pronoun introducing a clause
menos [zuì shǎo] — least — superlative form of 'little'
hablan [shuō huà] — talk — literally 'speak', but used for 'talk' in this context
