Antonyms for the phrase "break into pieces" include "assemble," "construct," and "create." These words imply putting something together rather than breaking it apart. Other antonyms include "combine," "connect," and "unify," which suggest bringing different parts together to form a whole. Synonyms for these antonyms include "build," "join," and "compose." These words highlight the opposite of breaking into pieces, which is to bring things together rather than tear them apart. In this way, antonyms for "break into pieces" focus on the positive aspects of creating, forming, and building rather than destroying.