Can give work to alien in the south, on reflection, but move fast (4,2,2)
I believe the answer is:
step on it
'reflection but move fast' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'can give work to alien in the south on' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'south' could be 's' (abbreviation) and 's' is found in the answer.
'on' is present in the answer.
'work' could be 'pit' (pit is a kind of work) and 'pit' is located in the leftover letters.
A single letter 'e' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for step on it that I've seen before include "Be quick" , "Hasten" , "Go for speed" , "Get a move on!" , "to flatten an insect?" .)