"The girl is reading a new book."
Translation:Dziewczynka czyta nową książkę.
A few seconds! Tell me where! I do have my notebook with all the terminations, yes, but dont carry it around. I see mostly duolingo in my phone. But even looking to the chart sometimes I have doubts, because some terminations are the same, like the genitiv and locatif, both plural and singular feminin (dativ also). I do need to find the logic beneath for it to make sense! For example, why Być demands instrumental?
Ok, so you just want know which case is used for one particular noun? Since you wrote "declinations" I assumed that you were looking for the entire declension table. That would be here.
I agree that case ednings often overlap, but with a little bit of effort you can guess the case in use in almost all instances.
http://sgjp.pl/leksemy/#255819/czyta%C4%87 tells you whether there is a strong rule regarding which case is required by a certain verb.
Also, there is a discussion about this topic here (if you scroll down a bit to FredFukada's comment).
Wau, nice tips, Djękuje bardzo! Don't mind my english, it's not my language... I mean in the translation above could have a small note of the declension used. So begginers like me would start associating things.