Would you accept the answer "probably not"?
In all seriousness, the answer to your question seems to be largely a
matter of definition. (It's much like the question whether Pluto and
more recently discovered objects in the distant solar system are
"planets.") Is a continent any land surrounded by water? Or is a
continent what we conventionally consider to be a continent? (To
complicate matters, I suppose we could say that "land" includes land
under water; but I think that would mean that there are no
continents!) There are scientific rationales for calling Antarctica a
continent, and Greenland part of North America. But there seems to be
an opening for an argument that they are both continents, at least
according to the general definition.
"Why is Australia considered an island and a continent, but Greenland
is not?" (Apr. 9, 2004)
"Re: Are Antarctica and Australia both considered islands and if not,
why not?", by Steve Williams (Nov 25 2000)
In general conversation, I wouldn't suggest calling Greenland a
"continent." However, to a geographer, you could raise the
possibility, even though I suspect that most geographers would
disagree. And the disagreement would presumably grow stronger for
smaller masses of land.
Search strategy --
Searched on Google for:
geography island continent