C2 Vocabulary

OPAL (Oxford Phrasal Academic Lexicon)

A set of four word lists for learners of English for Academic Purposes (EAP). These are the most important words to learn for writing and speaking academic English. Written words: 1200 words, divided into 12 sublists. Sublist 1 contains the most important academic words, with the next most important in sublist 2, and so on.
Spoken words: 600 words, divided into 10 sublists. Sublist 1 contains the most important academic words, with the next most important in sublist 2, and so on.
Written phrases: approximately 380 phrases, grouped by function, for example ‘specifying topics and relations between ideas’ (in terms of, in relation to, etc.)
Spoken phrases: approximately 260 phrases, grouped by function, for example ‘signposting and focusing in lectures/lessons’ (I was going to, I want to talk about, etc.)

The Oxford 3000 and Oxford 5000. The Most Important Words to Learn in English