[4] Under this definition, individuals that have some cultural connection with the language but do not speak it are not considered heritage students.
[8] As stated by Polinsky and Kagan: "The definition of a heritage speaker in general and for specific languages continues to be debated.
[10] The label heritage is given to a language based principally on the social status of its speakers and not necessarily on any linguistic property.
Thus, while Spanish typically comes in second in terms of native speakers worldwide and has official status in a number of countries, it is considered a heritage language in the English-dominant United States[4] and Canada.
[3] An additional factor that affects the acquisition of learners is whether they show willingness or reluctance towards learning the heritage language.
[15] One factor that has been shown to influence the loss of fluency in the heritage language is age.
[3] Researchers found that this phenomenon primarily deals with the memory network of an individual.
[7] An emerging effective way of measuring the proficiency of a heritage speaker is by speech rate.
The correlation is straightforward—lower proficiency speakers have more difficulty accessing lexical items; therefore, their speech is slowed down.
[18] Some heritage speakers explicitly study the language to gain additional proficiency.
Attrition, as defined by Montrul, is the loss of a certain property of a language after one has already mastered it with native-speaker level accuracy.
One argument against incomplete acquisition is that the input that heritage speakers receive is different from monolinguals (the input may be affected by cross-generational attrition, among other factors), thus the comparison of heritage speakers against monolinguals is weak.
Some colleges and universities offer courses prepared for speakers of heritage languages.