Welcome back to Thailand.
One phrase you will often hear in Thai is “na” at the end of a sentence or request. Adding “na” softens the assertion and makes it less confrontational, and in this sense it is slightly feminine (although used equally and appropriately by males and females).
Used judiciously it helps creates the appearance of being a highly principled and caring employee or boyfriend/girlfriend. The key word is “judiciously”, as too much use leaves you looking insincere, inarticulate or even a like a wannabe transsexual (a kathoey).
If this is your starting point in speaking Thai there is another word choice associated with using “na”, and getting it right will help avoid the potentially embarrassing consequences mentioned here.
Good luck na!