1. I forgot to bring the camera.

2. I forgot that I would bring the camrea.
3. I forgot that I should bring the camera.
4. I forgot that I had to bring the camera.
5. I forgot that I must bring the camera.

(Does #1 mean #2, 3, 4, or 5?)

1 answer

#1 could mean the same as any of the others, depending on the intention of the speaker. I see 1 and 2 as close to each other in meaning, and 3, 4, and 5 as close to each other in meaning.

The primary difference is in the meaning of the auxiliary verbs "would" and "must."