Qualitative methods in linguistics and sociolinguistics are often use when you are trying to understand participants perceptions, beliefs, and ideologies about language. Discourse analysis and critical discourse analysis are also frequently qualitative and rely on the researcher to interpret the data rather than a statistical procedure. The most common research strategies associated with qualitative methods in applied linguistics are interviews, observations (ethnographic fieldwork), and case studies.
It’s important to understand that, in general, qualitative research is not aimed at discovering something that is “true” or generalizable, but is concerned with the meaning associated with the data within the particular context in which the data was collected. For instance, if I wanted to understand how Latinx students felt about the use of Spanish on campus, I might interview a group of purposefully selected Latinx students and ask questions related to their perceptions and interpretations of what they experience. I might also observe in spaces where Spanish is used and record the interactions that I witness. These would result in text which I would analyze for meaning (content).