I did not read until teacher came in.
Does this sentence have these three possibilities when precisely analyzed?
1.I did not start reading before teacher came in, and started reading after teacher came in.
2.I did not start reading before teacher came in, but still not after teacher came in.
3.I didn't do the thing and that thing is "read until teacher came in". I.e. I may read before teacher came but not consistently read, and still claim I did not read until teacher came in.
Firstly, as this is a language learners' site, I hope you don't mind me correcting the sentence:
I did not read until the teacher came in.
In most variants of English, we don't address teachers by their profession. The only one I can think of is doctor. We do address people by their office, though: mayor, governor, professor, prime minister, but only when calling out to them: "Mayor! Governor! Professor!" But not _"Teacher! Lawyer! Electrician!"
When using it in a sentence, you should always use a determiner:
but not Teacher runs fast
Some mayors run fast.
... and so on.
As for your main question, in all senses I can think of, this implies that you continuously did not read.
The unmarked (usual) reading of the sentence is closest to the first, i.e.:
I did not read before the teacher came in, and started reading when the teacher came in.
I wouldn't use the second one at all. This seems highly marked (unusual) and you would probably say something like:
I haven't read (at all, today)
The third one is highly marked and there would be a large pitch movement at "read" to indicate it:
I didn't read until the teacher came in (, I wrote until the teacher came in)
^
And the emphasis is on you not reading until the teacher came in - you might have been writing until the teacher came in.
That's a great question. As a native speaker, I'd never thought about this ambiguity before!
The intended meaning is certainly #1. The structure is this happened until something changed, where this is "not reading".
Because "until" implies change (as mentioned above), #2 is not a correct interpretation.
As you said, the structure in #3 is this did not happen, where this is "reading until the teacher came in". It is a logical interpretation, but it is not how "not ... until" is understood.
If I wanted to say #3, I would need a different structure, e.g.
Most people read until the teacher came in, but I didn't.
(Other people were reading consistently, but I may have read sporadically, or not at all. Nothing is implied about what I did after, but it is implied that everyone else stopped reading.)
