Voiced vs voiceless consonant

One of 72 rules YabLab tracks in Russian writing.

A typical slip

Это мой старый школьный друк.

Это мой старый школьный друг.

The rule

Voiced vs voiceless consonant

Spelling rules connect a word’s sound, structure and conventional written form. The correction preserves the form readers expect to recognize.

Sound
Do not rely on hearing alone Several letters or spellings can represent the same sound, and some letters are not pronounced clearly.
Structure
Look for the word family Prefixes, suffixes and related words often reveal letters that speech hides.
Convention
Learn the complete pattern Spacing, hyphens, accents and capitals are part of a word’s spelling, not decoration.

What YabLab does with this mistake

  1. Catches it right as you write — comments, email, docs.
  2. Explains the why in your language, not just the fix.
  3. Helps you practice it until it is gone for good.