If the word is omitted through the grammar, should the meaning of the word be omitted together?
For example, I saw James working out as (he did) before.
You see there disappeared ‘he did’ between ‘as’ and ‘before.’ Then the meaning of ‘he did’ disappeared together?
Sometimes a word that is omitted can be deduced. For example in parallel constructions:
John went for a walk, but Mary didn't.
In this construction the words "go for a walk" have been omitted. But their meaning can be deduced. The sentence means "... but Mary didn't go for a walk."
But in general, omitted words can't be deduced.
John went for a walk.
Here I have omitted the words "to the shops". You can't deduce this from the words I said. So the meaning of "to the shops." is omitted completely.
I hope you can see how the two examples are different.
Most often, omitting qualifiers like this leads to ambiguity, rather than changing the meaning, since the listener doesn't know what you omitted.
So:
I saw James working out as before.
Could be:
I saw James working out as he worked out before.
Or:
I saw James working out as I saw him before.
You have to decide if your listener is likely to guess the correct version, or whether you need to be more specific.
I don't think it makes sense to say it "removes the meaning" - the "as before" still tells the listener that it cannot mean:
I saw James working out for the first time
Obviously if you remove enough, then the sentence has so many possibilities that you are no longer communicating the same thing:
I saw James
This includes all the previous possibilities, but the listener has no hope of guessing the details you've missed out.
