Fine words butter no parsnips
Nothing is achieved by empty words or flattery.
This proverbial saying is English and dates from the 17th century. It expresses the notion that fine words count for nothing and that action means more than flattery or promises. You aren't very likely to come across 'fine words butter no parsnips' as 20th century street slang - you are more liable to hear it in a period costume drama.
Potatoes were imported into Britain from America by John Hawkins in the mid 16th century and became a staple in what established itself as the national dish - meat and two veg. Before that, various root vegetables were eaten instead, often mashed and, as anyone who has eaten mashed swedes, turnips or parsnips can testify, they cry out to be 'buttered-up' - another term for flattery. Indeed, the English were known for their habit of layering on butter to all manner of foods, much to the disgust of the French who used it as evidence of the English lack of expertise regarding cuisine and to the Japanese, who referred to Europeans in general and the English in particular as 'butter-stinkers'. This butter habit is evidenced in the various forms of the expression that are found in print in the 1600s - 'fine/fair/soft words butter no parsnips/cabbage/fish/connie[rabbit]'. A typical example is this verse from John Taylor's Epigrammes, 1651:
Words are but wind that do from men proceed;
None but Chamelions on bare Air can feed;
Great men large hopeful promises may utter;
But words did never Fish or Parsnips butter..
The earliest version that I know of in print is in John Clarke's Latin/English textbook Paroemiologia, 1639:
Faire words butter noe parsnips, verba non alunt familiam. [words, no family support]
That's all, no more fine words from me.
See also: the List of Proverbs.