昨天回家了？

[freefall]

Okay, so take the sentences:

爷爷回家了！

爷爷回家来了！

Grandpa's come home!

This sentence indicates an emerging situation, hence the sentence-terminating modal version of 了.

How would you convert these sentences to past-tense narration? From my experience, you accomplish this by placing the 了 directly after the verb, where it becomes aspectual and indicates prior completion of the action?

昨天爷爷回了家。

昨天爷爷回了家来。

Or omit 了 because the (directional complement) / (昨天 adverb) indicate completion of the action?

昨天爷爷回家。

昨天爷爷回家来。

So which, if any, of the above four sentences is correct? Which is best?

I did some googling and found abundant examples of this construction:

昨天爷爷回家了。

I'm a little confused because this seems to be employing the modal particle 了 (sentence terminator) to narrate a past action. Is that sentence okay? Is Chinese just more flexible than I thought?

Thanks very much for the great help! You guys are an unparalleled resource for my picky grammar questions.

[tanhql]

来 should not be in any of the sentences, maybe except for the first example.

了 should be in the past tense sentences.

昨天爷爷回家了 sounds fine.

爷爷昨天回家了 also sounds fine.

[nitbj]

1.爷爷回家了！

2.爷爷回了家！

了 in 1 and 2 are grammatically different.

了1 make functions with the whole sentence which indicate 'an emerging situation' as you said, while 了2 indicate the completion of the verb回 which likely functions as a past-tense.

Therefore, the two sentences get different indications.

S1:爷爷 came home (from outside to home)

S2:爷爷 came home (not outside, already at home)

来 is used in spoken lanuguage, for me, all of the examples are acceptable.