I have collected data for my qualitative case study 3 years back (through classroom observations, ethnographic notes, artifacts, interviews, etc.) related to the use of pupils' first language in learning English. All these data have been transcribed and initially analyzed. However, due to global pandemic and series of lockdowns I was not able finish my study (final/full paper report). When I resumed graduate school study recently, the issue on the validity of my research data was raised. I am anxious that I might be advised to re-do it again. As I study the circumstances and issues under study, (use of first language in learning the English language), nothing has changed with the practices in pre-pandemic and post-pandemic educational classroom setting. Similar language practices and features can be observed. Please help me on this. I hope you can cite authorities to back up my justification.Thank you and God bless.