Using who, which, and that to join sentences (e.g., "That is the man who lives next door").
Pre-intermediate English grammar (often aligned with the of the CEFR) is the bridge between basic survival English and being able to express complex ideas. Grammar in Use - Pre-intermediate
Using "for" for a period of time (for 2 years) and "since" for a starting point (since 2021). Articles: Overusing or omitting "a," "an," and "the". Using who, which, and that to join sentences (e