How do you tell if synonyms of “almost” default to meaning “less than”?

Having just had a chat with Em1, I noticed that some words or phrases that mean almost will mean less than when used alone, and other synonyms will mean greater than.

For example, nearly and close to seem to mean less than when used alone:

• You’re nearly 30!
• You’re nearly there.
• We’ve close to the required number of participants.

Whereas barely and just seem to mean greater than or equal to:

• He’s barely 18!
• We’ve barely enough for breakfast.
• We’ve just finished.
• They’ll just be coming over the hill.

If you swap any of the adverbs around then the meaning goes with them. However, if you change the context a little bit then the meaning can switch around:

• 31 is close to 30.
• We’re just short of the required number.

If we take the over/under question of Em1:

The village is located [almost] 30 km to the south of London.

How can you tell if a synonym for almost means less than or greater than?

This is a really complicated question, and the answer is not simple. This phenomenon involves Negation, Quantification, and Metaphor, and that’s already too much for a short answer. I’ll try, though.

The words in question are called “approximatives” in the trade. They are adverbs of degree, I suppose, if one must put a POS tag on them, and they function to add some precision to quantification. What they mean generally depends on what metaphor they’re instantiating.

It’s like calculus — how to describe precisely the experience of approaching some kind of limit in a continuous event or state. Without math. This is not easy, so we use metaphors instead.

There are several kinds of measured continuity that humans naturally experience, leading to several kinds of natural metaphor for humans measuring continuity. They can measure, as it turns out, linear motion (JOURNEY metaphors), or they can measure accumulation (CONTAINER metaphors).

• Motion metaphors: Personal Experience (LIFE) is Personal Motion (JOURNEY)
• (There is a directionality to this metaphor, so these all imply not there yet)
• almost/nearly/practically at the 50-yard line/goal/limit/right age/border
• Container metaphors: LIFE is Accumulated Memory (CONTAINER)
• (think a big jar of memories, piling UP as they get MORE — a vertical linear model)
• pass/over/under/up to the mark/the top/the time limit/two years/ten million rubles
• (or think a cupboard full of memories, which may be full or bare)

So, one point is that these are both vectors — they have a starting state (BEGINNING, EMPTY), they have an ending state (FINISH, FULL), with a continuous range between them, and the directionality is one-way (FORWARD, UPWARD). That means that purely locative phrases like near or close to mean “not yet” only if they’re interpreted as directional metaphors; it isn’t intrinsic to their meanings.

A second point is that some of these terms are intrinsically negative, and can trigger NPIs like ever. Let me just say that this does not make the grammar any simpler.

• I seldom/rarely ever see them.
• He hardly/scarcely ever gets it right.

A third point is that there is a personal and temporal dimension to these metaphors. Abstract concepts like emotion and time are almost impossible to talk about without metaphor, and they permeate almost all our metaphors.