The phrase "apt to do something" indicates a likelihood or tendency to perform a particular action. Synonyms for this phrase include "likely to do something," "prone to do something," "inclined to do something," and "disposed to do something." Other synonyms include "predisposed to do something," "tending towards doing something," and "have a knack for doing something." All of these phrases convey the same meaning and can be used interchangeably in conversation or writing. Using synonyms can add variety and color to your language and prevent repetition in your writing.