Delivery

unnatural pauses

unclear words

lack of intonation and stress

wrong pronunciation

Language Use

grammatical errors

corrected

wrong words

corrected

repeated patterns

recommend

repeated words

recommend

number of complex structures

number of idiomatic expressions

paraphrase (original)

paraphrase (new)

Topic Development

unclear relationship

corrected

lack of coherent devices

recommend

lack of specificity

recommend

wrong information

corrected

timing (seconds left, incomplete the answer)