"Tha Ealasaid gu math."

Translation: Elizabeth is well.

[Endless_Winter]

So Math can also mean 'well', why not Good in this case cause that's what gu Math has been in previous lessons.
When do you know when to use which one or is it acceptable to interchange as they have the same meaning in the end?

[silmeth]

Math means good, it is an adjective. Gu before adjectives turn them into adverbs, thus gu math is well. Also gu math is often used as an intensifier like English really or quite, eg. gu math dorcha really dark (literally well dark).

In what lesson gu math has been translated as good (and not well)?