Online corpus resources
Corpora
Corpus of Contemporary American English (COCA) 1 billion words (80% written; 20% spoken)
https://www.english-corpora.org/coca/
British National Corpus (BNC) 100 million words (90% written; 10% spoken)
1980s-1993
https://www.english-corpora.org/bnc/
Michigan Corpus of Spoken Academic English (MICASE)
British Academic Spoken English Corpus (BASE)
&
British Academic Written English Corpus (BAWE)
Academic Vocabulary Lists (based on the COCA)