The ICAO English proficiency test:
The ICAO rating scale has six levels. Level 1 is the lowest and Level 6 the highest you can achieve. Level 4 is the so-called “operational level” which is the level you will need to achieve at least if you want to pass the test.
Moreover, you are tested in six language areas: pronunciation, structure, vocabulary, fluency, comprehension, and interaction. There is no cumulative score. This is a rule set by the ICAO meaning that you must achieve at least level 4 in all six language areas. In case you can achieve the highest score, Level 6 you will only have to do this test once in your life.
Hence, Ladies and Gentlemen preparation is key. There will be listening comprehensions where you will have to repeat the information said (mostly from air traffic control via radio transmission) back to sender in the correct way as a pilot.
As stated in the official Manual on Radiotelephony published by the International Civil Aviation Organization (ICAO) in 2007, it is advised that in order to expedite radiotelephony communication the use of phonetic spelling should be dispensed with if there is no risk of this affecting correct reception and intelligibility of the message. The requirement for air traffic personnel and pilots to demonstrate their proficiency in English was introduced in 2011 by the ICAO. The test regarding the language proficiency requirements were introduced as the result of a series of severe incidents as well as accidents in which communication or a lack of language skill were contributing factors.