Get grandpa to island to get a grip on regional dialect (6)
I believe the answer is:
patois
'regional dialect' is the definition.
(I've seen this before)
'get grandpa to island to get' is the wordplay.
'to get' indicates the answer is hidden within the clue (I've seen 'got' mean this).
'PATOIS' can be found hidden inside 'get grandpa to island'.
'a grip on' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for patois that I've seen before include "Jargon or vernacular" , "'Argot, vernacular (6)'" , "Dialect or jargon" , "Dialect or non-standard language" , "Language of group" .)