nuances - What's the difference between ぜひ and きっと when inviting someone to do something?

You can say for example

• ぜひパーティーにいらしてね


• そのうちまた是非お出かけください



• 「今晩お伺いしてもいいですか」「ぜひどうぞ」

and

• きっと来てくださいね


• きっと訪ねて来てください

I would translate both ぜひ and きっと in these sentences with "by all means", but I'm sure (as always), there's a nuance in meaning when you use either. Could someone please explain this nuance? Thanks!

Answer

Comparing

ぜひ来てくださいね。
きっと来てくださいね。

ぜひ expresses a hope/wish, whereas きっと expresses an expectation. (必ず would express obligation.)

A teacher telling his students "きっと来てくださいね" means more like "I am expecting everyone to come". Thus きっと feels stronger (it's an expectation, after all), but may just mean that whoever is inviting really wants you to come.

Maybe it's a bit like this

また来てくださいね。
See you (again).

ぜひ来てくださいね。
Please (by all means) come again.

きっと来てくださいね。
You'll come again, won't you?
You'll have to come again. (friendly tone)

必ず来てくださいね。
You are required to attend.