“a website”...”their”
maybe “its” would be better
The distinction is whether "website" is being used as a count noun or as a mass noun. I treated it as a count noun, though most, I acknowledge, would treat it as a mass noun.
In either case, however, "website" and "their" are not verbs, and therefore do not have tenses.
p.s. I had to look all that up, so perhaps I was just lucky.
Well, I guess since we were talking about a singular entry for correction, I guess I wrongly assumed that when you said “a” you were referring to one singular website, and not a subcategory of nouns that would of course make your corrections faultless, while still sounding silly.
If their is correct, then I guess my personal preference would be not to add the “a” to a “count” noun.
My bad.