begin vs break in

begin and break in both are verbs.

Word	Noun	Adjective	Verb	Adverb
begin	No	No	Yes	No
break in	No	No	Yes	No

As verbs, break in is a hyponym of begin; that is, break in is a word with a more specific, narrower meaning than begin:

begin (verb)	break in (verb)
take the first step or steps in carrying out an action	make submissive, obedient, or useful
set in motion, cause to start	break so as to fall inward
begin to speak or say	start in a certain activity, enterprise, or role
begin to speak, understand, read, and write a language	break into a conversation
achieve or accomplish in the least degree, usually used in the negative	intrude on uninvited
begin an event that is implied and limited by the nature or inherent function of the direct object	enter someone's (virtual or real) property in an unauthorized manner, usually with the intent to steal or commit a violent act
have a beginning, in a temporal, spatial, or evaluative sense
be the first item or point, constitute the beginning or start, come first in a series
have a beginning characterized in some specified way
have a beginning, of a temporal event