Possible Clues:

• Warn a pretty girl about a Scotsman
• Rebuke
• Caution a looker about Scots man
• Caution
• Warn a good-looking person about first day at work, perhaps
• It's the turn of father to tick off the Scotsman to his confusion
• A Scotsman in a big plate to put one in one's place
• Forewarn drunken nomad prior to his collapse
• Caution — a certain food keeps only half a day
• Caution a very attractive girl covering half a day