this didn't / that didn't

No rule, just usage.

"That didn't" sounds better.

Go by ear with this.

Proximity. This denotes closeness (geographical, temporal, mental, etc.), and that distance.

Compare:


In your example, depending on the context, it could go either way. That didn't sounds more natural as a default, though.

SomethingOrOther said:

Proximity. This denotes closeness (geographical, temporal, mental, etc.), and that distance.

Click to expand...

I think this is the key point. The original text is:

"They're dead."
"Well, this didn't escape our attention."

Click to expand...

What I hear is that the first character is informing the second character of something that s/he didn't know. That makes the information feel distant to the second character, because s/he didn't know it until s/he was told.

(What makes me think that s/he didn't know it until told? The "well." It's the sort of thing one says while processing a piece of information while keeping the conversation flow going. If the character had said, "This didn't escape our attention." then I would assume that s/he knew already, and was revealing a deeper knowledge to the first speaker. Possibly while stroking a white cat, steepling fingers, or otherwise being faintly ominous.)

This is me picking apart an initial, immediate reaction. Naturally, one doesn't normally analyze to this degree.

SomethingOrOther said:

Proximity. This denotes closeness (geographical, temporal, mental, etc.), and that distance.

Compare:

A) "It's freezing. I wish I had my jacket."

"Yeah, this sucks."

B) "We had record-low temperatures the other day. Some guy without a jacket almost froze to death."

"Whoa, that sucks."​

In your example, depending on the context, it could go either way. That didn't sounds more natural as a default, though.

Click to expand...

Correct, and well put.

And it doesn't really matter when you're talking about things that are not concrete.

It hardly matters. "This" often tends to indicate someting closer in time or space, while "that" tends to indicate something farther away, but sometimes the two are simply used to distinguish one thing from another: "This pair of socks is cheaper than that one."

The ear is a good guide. If someone says, "Ted won the marathon despite having a prosthetic leg," I'd be more likely to say "That's amazing," than "This is amazing." But they are both correct.

When you say "that" you are pointing to something over there. When you say "this", you are pointing to something that is right here, right now.

If I'm walking down the street with the Mem, sometimes my eye catches sight of a pretty young thing. I'm sorry. I can't help it. I'm a red blooded male.

And at that point I might say something along the lines of "That young lady fills her clothes rather well."

Quickly followed by the Mem saying: "And this is who you married."

Sexist, moi? Hey, she checks out the male joggers as they jiggle past.