I have read many a novel set in the Regency period where la is used in conversations.
La, Susan, don't be so bothersome
What is its purpose and correct use?
Thank you for your insights.
You are referring to the use of la as an exclamation. According to M-W:
- interjection chiefly dialect —used for emphasis or expressing surprise
Interjection la (from Wiktionary)
(obsolete) Used to introduce a statement with emphatic or intensive effect. (archaic) Expressing surprise, anger. etc.
- 1811, Jane Austen, Sense and Sensibility, vol. III ch. 2: “Oh, la! here come the Richardsons. I had a vast deal more to say to you, but I must not stay away from them any longer.”
Etymology: from French la, Italian la.