This is wrong because mums is in dative and cannot maintain an agreement with the verb. The subject of the first part is cukura, which requires the verb būt to be in the third person. Now, you only have to turn nav in the imperfect, which is nebija.
Mums nebija cukura.
A very literal translation is:
To us, did not exist [any] of sugar.
Thanks a lot, that cleared it up for me, and showed that I have a LOT of learning to do.
This may be a bit off topic, but is there any definitive book or learning method with Latvian? I haven't been able to find too much, and any help would be greatly appreciated! Feel free to send me a Private Message or email through this forum, if it isn't welcome in this thread.
The best way to learn Latvian, probably, is by communicating with Latvians. I don't think that any books would be of much help....since Latvian grammar is something that drives crazy even Latvians...!!!