In addition to the heterotrophs, there are many kinds of autotrophic bacteria, able to produce their own food. These autotrophs may be photosynthetic or chemosynthetic and may or may not use oxygen in their synthetic pathways. Cyanobacteria are the largest group of photosynthetic eubacteria. The cells of these bacteria are often much larger than other bacteria, which in the past led this group to be classified as algae rather than bacteria. In fact, cyanobacteria are still sometimes referred to as blue-green algae.
Polyglotism or polyglottism is the ability to master, or the state of having mastered, multiple languages. The word is a synonym of multilingualism, but, in recent usage, polyglot is sometimes used to refer to a person who learns multiple languages as an avocation.
Monolingual: A person knowing only one language (40% of world population) Bilingual: A person using or able to use two languages especially with equal fluency (43% of world population) Trilingual: A person speaking three languages fluently (13% of world population) Multilingual: A person who speaks more than two languages, but used often for four languages or more (3% of world population speak more than 4 languages) Polyglot: Someone with a high degree of proficiency in several languages (less than 1â° of world population speak 5 languages fluently)