Tim Marr is Visiting Professor in Applied Linguistics at Universidad Icesi, Cali, Colombia. He was formerly director of the MA TESOL programme at London Metropolitan University and has over 30 years' experience in teaching and researching language and linguistics, as well as training language teachers. He has co-authored several books on linguistics and TESOL.

Steve Collins is Head of English at Bishop Luffa School, Chichester, where he teaches Key Stages 3 to 5, specialising in A Level English Language. He has taught in secondary schools for 20 years, and also taught EFL in Peru and the UK. He contributed a chapter on sentence-level analysis to the Routledge book Teaching English Language and Literature 16-19.