Platforms like Quill.org provide diagnostics to identify specific learning gaps in writing and grammar. Quill.org | Interactive Writing and Grammar Platforms like Quill

Vowels and consonants, stressed and unstressed vowels, and the use of the soft sign ( ь ). stressed and unstressed vowels

Simple morphemic analysis (root, prefix, suffix) and rules for word hyphenation. Platforms like Quill

Books like "Russian Language. Multi-level Tasks. 2nd Grade" by N.S. Ulyanova provide comprehensive collections for independent testing.