"Today's dinner does not taste good at all."
I tried to use まったく in this context and was rejected. Is it not appropriate with negatives?
Hirugohan is daytime rice/meal (lunch). Yuuhan is nighttime meal (dinner).
Does anyone know any good grammar tools? Long sentences like this trip me up
Try to take a look at Human Japanese application, very nice detailed explanations are provided there. I use Duolingo, Lingodeer, Memrise and HJ and I found out, that they complement each other pretty nicely.
What exactly you don't understand on this particular sentence?
晩御飯 is so rare i'm not surprised it's not accepted. 晩ごはん and 晩ご飯 are significantly more common forms.