Timeline for I received a gift from my sister who just got back from

6 events

when toggle format	what		by	license	comment
Jun 13, 2019 at 13:01	history	edited	Enguroo	CC BY-SA 4.0	added 6 characters in body
Jun 13, 2019 at 1:42	comment	added	KRyan		I think it is probably worth mentioning, since this is ELL, that English authors are unlikely to be totally scrupulous about the use of this comma. It may well be present for non-defining cases and absent for defining cases, just because that matched the presence/absence of a pause in the author’s mind. As always, “rules” of the English language are an attempt to categorize how people speak and write, but speakers and writers tend to just go with what sounds right to them. Wouldn’t want someone reading this to be confused as assume something must be defining because there is no comma.
Jun 12, 2019 at 23:22	comment	added	Barmar		Note that the reason there's no need to define which sister could also be that you don't think it matters to the audience. They don't know your family, so the distinction is irrelevant.
Jun 12, 2019 at 11:20	history	edited	Enguroo	CC BY-SA 4.0	added 133 characters in body
Jun 12, 2019 at 11:11	comment	added	Lucian Sava		And, this is a very good answer as you explain that's up to the writer (certainly a careful writer) whether to put a comma.
Jun 12, 2019 at 11:06	history	answered	Enguroo	CC BY-SA 4.0