Abbreviations used in the text
AVL
New Academic Vocabulary List
CEFR
Common European Framework of Reference for Languages
COCA
Corpus of Contemporary American English
EFL
English as a Foreign Language
ESL
English as a Second Language
IPA
International Phonetic Alphabet
IRET
Institute for Research in English Teaching
L2
learner’s foreign language
LOB
Lancaster-Oslo-Bergen corpus
NLP
natural language processing
NSM
Natural Semantic Metalanguage
PACE
Perkins Approved Clear English
RVL
receptive vocabulary load
STE
Simplified Technical English
ukWaC
the corpus of British English compiled from the .uk domain
WSC
the Wellington Corpus of Spoken English (New Zealand)
WSD
word sense disambiguation