Complex sentence: In 2012, Tubosun started an online campaign to demand that Twitter include Yoruba in the list of languages into which Twitter was being translated: 1 March 2012 was declared "the Tweet Yoruba Day" to call attention to the matter.
Split into simpler sentences: In 2012, Tubosun started an online campaign, to demand that Twitter include Yoruba language in the list of languages to which Twitter was being translated. March 1,2012 was declared "the Tweet Yoruba Day" to call attention to the matter.