This chapter presents and analyzes the phenomenon of heritage language development using data from bilinguals for whom English is the weaker language; their stronger languages are French, Japanese, or Hebrew. Heritage English is different from the baseline language in a number of respects, for example, in the use of discourse fillers, particle verbs, or in the knowledge of relativization strategies. However there are also a number of properties that remain intact in Heritage English; they include near-native pronunciation, good control of tense and determiner phrases, and comprehension that is superior to that of L2 speakers. The chapter emphasizes the importance of equally considering the ways heritage speakers remain faithful to the baseline ("what they get right") and the ways in which they diverge from the baseline.