Limited: Very limited vocabulary causing great communication difficulties. Reasonable comprehension when the speaker speaks slowly.
Basic: Can converse simplistically with a single person but with restricted active vocabulary. Good comprehension of a single speaker.
Average: Excellent passive vocabulary in a range of topics but difficulties with speaking at good tempo. Good comprehension of relatively simple conversations.
Good: Can speak freely and confidently with good vocabulary. Excellent comprehension and competent to write routine business letters and reports.
Advanced: Can speak fluently with extensive vocabulary and advanced comprehension. Has writing abilities comparable to an educated native's and can carry out nearly all writing tasks quickly and correctly.
Excellent: Native in speaking, writing and understanding