determined usage with no phonetic meaning (like Russian: туш 'fanfare' and тушь 'India ink', both pronounced /tuʂ/ but different in grammatical gender and...

feminine marker for singular nouns in the nominative and accusative; e.g., тушь ('India ink', feminine) cf. туш ('flourish after a toast', masculine) — both...

Examples include: порог — порок — парок, луг — лук, плод — плот, туш — тушь, падёж — падёшь, бал — балл, косный — костный, предать — придать, компания...

just orthographic; e.g. Russian туш, tush [tuʂ] 'flourish after a toast'; тушь, tushʹ [tuʂ] 'India ink'. In some languages, a hard sign ⟨ъ⟩ or apostrophe...