Some perched and some got left (7)

'some' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'perched and some got left' is the wordplay.
'perched' becomes 'alit' (I've seen this in another clue).
'and' says to put letters next to each other.
'some got' becomes 'elt' (I can't justify this - if you can you should give a lot more credence to this answer).
'left' says the letters should be written in reverse.
'elt' written backwards gives 'tle'.
'alit'+'tle'='ALITTLE'

Can you help me to learn more?