Question about grammar "It's been a while since I've ~" and "It's been a while since I ~"
Solution 1:
Grammatical Correctness
I believe both are grammatically correct. If you take out the apostrophes you can write:
It has been a while since I have sat at a dinner table together with a family.
and
It has been a while since I sat at a dinner table together with a family.
Both seem fine to me.
Which is More Commonly Used
The best I could come up with for which is more common turned up the following (from Google books searches):
I've * Variants
"been a while since I've" OR "been a while since I have"
About 158,000 results
search results
I'd * Variants
"been a while since I'd" OR "been a while since I had"
About 50,800 results
search results
I * Variants
"been awhile since I" -"I've" -"I had" -"I have" -"I'd"
About 11,600 results
search results
You can also see a similar story unfolding by looking at google Ngram viewer using "been a while since I *".
Subtle Meaning Differences
As for the subtle differences, I think it boils down to the tense of the verb to sit.
-
I satis the simple past and is used to
express the idea that an action started and finished at a specific time in the past. Sometimes, the speaker may not actually mention the specific time, but they do have one specific time in mind.
http://www.englishpage.com/verbpage/simplepast.html
-
I have satis the present perfect and is used to
say that an action happened at an unspecified time before now. The exact time is not important.
http://www.englishpage.com/verbpage/presentperfect.html
Solution 2:
There are many nuances in this sentence:
"It's been a while since I sat at a dinner table together with a family."
The first question is whether 'a while' or 'awhile' is correct. 'Awhile' is the adverb and should never follow a preposition. For these reasons, I prefer 'awhile.'
Second is the verb tense in the subordinate clause. To my ear, 'since I have sat' sounds odd. I prefer 'since I sat...' A further reason for choosing this option is that it is in keeping with the law of concision. If you can express what you mean in 5 words, why use 6? Hence, chop off the helping verb 'have.'
The third question is the adverb 'together.' Isn't the meaning of this word included in the preposition 'with'? If so, it is unnecessary. To test if I'm right, read the sentence without 'together.' I find no appreciable gain in meaning. Do you? I find redundancy instead.