Quick question?

It looks like Word was having trouble identifying the subject of the sentence.

These sentences came up as gramatically correct in my version of Word:

• The only light in his sparse dwelling was from an assortment of candles.
• The only light in his sparse dwelling were from an assortment of candles.
• The only light was from an assortment of candles.
• The only light were from an assortment of candles.
• The light in his sparse dwelling was from an assortment of candles.
• The light in his sparse dwelling were from an assortment of candles.

Adding "that was" after light produces ("The only light that was...") the correct grammatical response. Interestingly, removing "only" and "in his sparse dwelling" also produces the correct grammatical response. As does replacing the word 'light' with 'brightness' in the original sentence.

I'm not surprised Word has a problem with the word "light" - it's an adjective, a verb, a mass noun and a count noun - and each of those parts of speech works differently in sentences.

Computers have real problems identifying whether a sentence is grammatical or not, because no one's figured out a way to get a computer to parse language correctly. It's a similar reason why machine translation results are dubious at best.

I turn the grammar checker off when I'm writing.

"Was" is correct. "The light...was." Don't trust a computer to do grammar.

But "The only light in his room came from an assortment of candles" is a bit more interesting. Or "An assortment of candles provided [gave, furnished, dispensed] the only light in his room."

Just as an alternative (a bit more show versus tell):

Candlelight flickered and fitfully divided the pitch in the sparse dwelling.

As noted, "was" is of course correct. But the initial confusion in this sort of disconnected subject-verb agreement can itself be a signal of a grammatically correct, but clumsy, sentence, or at least a sentence that could be rephrased into a more succinct and straightforward form (like the one I just wrote here is).

One should never write too early in the morning.

caw.