A number of demolinguistic descriptors are used by Canadian federal and provincial government agencies, including Statistics Canada, the Commissioner of Official Languages, the Office québécois de la langue française to assist in accurately measuring the status of the country’s two official languages and its many non-official languages. This page provides definitions of these descriptors, and also records where and for how long each descriptor has been in use. Descriptors used in the census (primary descriptors) "First official language spoken" This measure is based on: first, knowledge of the two official languages: second, mother tongue; and third, the home language (i.e., the language spoken most often at home). The first official language spoken may be: English only, French only, both English and French, or neither English nor French. Data for this descriptor were first collected in the census of 1986. "Home language" Home language is the language most often spoken at home at the time of the census. Because some couples have different mother tongues, the census allows individuals to indicate that they speak more than one language at home. Persons who live alone may not speak at all in the privacy of their own homes, so the census asks such individuals to identify the language in which they feel most comfortable. Data for this descriptor were first collected in the census of 1971. Inclusion of a question along these lines was recommended in the report of the Royal Commission on Bilingualism and Biculturalism, which highlighted the shortcomings of the mother tongue measure: On this basis, the commissioners made the following additional statement: "If a question on the language generally used is added to the census—and if the data gained from the responses to this question are considered valid—we think this should be used as a basis for future calculations [as to where services ought to be offered in which language]." "Knowledge of Official Languages" This measure describes which of the two official languages of Canada a person can speak. In Canada, knowledge of both official languages is referred to as "bilingualism", even though bilingualism can technically mean a knowledge of any two languages. This descriptor relies on the census respondent’s own evaluation of his/her linguistic competence. Some people claim that this reliance on each Canadian’s subjective opinion leads to over-reporting of bilingualism, because many people with only a limited ability to speak the other official language record themselves as having