This cross-sectional study explores the linguistic development of Greek children learning English as a Foreign Language in the same bilingual immersion preschool, before and after lockdown. 66 children between 5;5 and 6;4 (31 tested in person in June 2018 and 35 tested online in June 2020) completed the BPVS and the TROG in English. The 2018 group scored significantly higher on the vocabulary measure but not the grammar measure. The drop in BPVS scores observed in the 2020 group could be a consequence of the reduced English language input that children received during lockdown. The lack of a drop in TROG scores could indicate that grammar is not as sensitive to reduced input.