February 21 is International Mother Language Day, a UN-sponsored event meant to promote linguistic and cultural diversity. In Belarus, one's mother language can sometimes be a thorny question. Both Belarusian and Russian are official languages, but Belarusian has gradually been marginalized in schools and government offices in recent years. In a 2009 census, 53 percent of respondents named Belarusian as their native language, down 20 percent in 10 years. Less than a quarter said they always speak Belarusian at home. When RFE/RL's Belarusian Service asked people in Minsk to name a favorite Belarusian word or phrase, some were inspired to quote poetry or bits of slang -- but many others struggled to find words.