"Since" vs "that"

Question

I read explanations: ""Since" is a length of time stretching from a point in past time up to the present, while "that" is merely introduces a tensed clause.", "We use 'since' followed by a point in time, not a period". There is the sentence:

• "It was several years since/that I had been travelling that road."

I was told "since" is needed here. But, as far as I understand this sentence: "It was (a some point in time) that (in which) I (already) had been travelling that road." So, according the explanation, I think there must be "that", isn't it? May be there is context where "since/that" are both possible?

Another sentence that was offered to me:

• "It had been several years since I traveled that road."

I understand this sentence this way: "By some point in the past some time had passed after the last time I traveled the road". So in other words: "(By that time) several years had passed since I traveled that road." - right?

Another sentence, that I was told is clumsy but correct:

• "It had been several years since I had been traveling that road."

-is confusing for me, could you please explain the meaning to me?

Answer 1

First,

It had been several years since I travelled that road

and

It had been several years that I travelled that road

are both grammatically proper and idiomatic, but they have different meanings.

The first sentence means that, at some instant A in the past, the speaker had last travelled on that road at instant B, which preceded A by several years.

The second sentence means that at some instant A in the past, the speaker had started travelling on that road at instant B, which preceded A by several years, and had continued to do so up to, or almost up to, A.

Both are good sentences, but have quite different meanings.

I am not sure whether using the past perfect in the subordinate clause after having defined the time period with the past perfect in the main clause is grammatical. It is certainly rare. But it does not affect the meaning if used.

Does this help?

Answer 2

It was several years since/that I had been travelling that road."

Since and that are not organically connected. The have no intrinsic connection.

Past tense, past meaning: It was several years since I traveled, had traveled or had been traveling that road.

Now, one does hear people saying things like:

It's been several years that I haven't seen him. [negative is required for the meaning]

If you use a since phrase, you get:

It's been several years since I've seen him. [same meaning as the other but a negative cannot be used].

If a situation is described in a simple past tense, and then something happens before that, this:

"We went hiking that summer as we did all previous summers. But it had been several years since I had been traveling up that road."

is perfectly fine.

Answer 3

The explanations you read sound correct. In each of your examples, the "span of time" is "several years," so you should use since. For the sentences to be correct, however, the tense you use in the first and second parts of the sentence must agree.

Example 1:

It was several years since I had been travelling that road (incorrect)
  (past tense)           (past perfect progressive - does not agree)   

Should be past tense or past perfect tense:

It was several years since I had travelled that road

It had been several years since I [had] travelled that road.

Example #2:

It had been several years since I travelled that road. (correct)

That sentence is correct. The span of time is "several years," so you use since. The first part of the sentence is past perfect tense and the second part is the past tense, so they agree.

It means that since the last time you travelled that road, several years have gone by (and finished -- past tense).

Example #3:

It had been several years since I had been travelling that road.

It might be correct, but it is very awkward and isn't likely to be used. But, for the same reason, you use since. And you have the tenses agreeing in the first and second parts of the sentence.

The meaning implies that you were travelling that road on some kind of regular basis (had been travelling) and you stopped. And then a few years went by. And now you are in the present, talking about the past.

It can be very confusing. You can read more about it here.