Les niveaux de connaissance en langue ont été classés et définis par le Conseil de l'Europe. Cette norme européenne, appelée cadre européen commun de référence, est acceptée et reconnue dans tous les pays de l'Union Européenne. Elle détermine précisément les compétences que doit posséder l'apprenant pour communiquer dans certains contextes.
Towards the end of May 2000 an underwater volcano called Kavachi erupted in the Solomon Islands in the Pacific Ocean. It has formed what geologists say is a new Pacific island. An international team of scientists arrived at the site expecting to find a dormant volcano, instead they witnessed a spectacular show. Kavachi had become active and was sending molten lava to up to 500 metres into the air every fifteen minutes. Brent Innes, an Australian geologist, said that it had been totally unexpected. He explained that they had arrived at the site to find waves breaking on the peak of the volcano. They were able to film the rare event and collect data on volcanic eruptions.