6th grade focuses heavily on noun and adjective declensions. Make sure your cases match!
Since you're looking for help with Efremova’s 6th-grade Russian workbook, I’ve put together a short essay (сочинение) on a classic theme usually found in that curriculum: gdz russkii iazyk 6 klass rabochaia tetrad e.a efremova
Лес в осеннем убранстве (The Forest in Autumn Dress) 6th grade focuses heavily on noun and adjective declensions
Pay close attention to the "soft sign" (ь) in -тся and -ться endings. gdz russkii iazyk 6 klass rabochaia tetrad e.a efremova