A lot of entries for English words simply say, “Not used in Japanese.” You might think this would make speaking easier, but usually it doesn’t. Sure, determiners like “a” and “the” are easy to get by without, but “both”, “other”, “be”? Those words are a little more consequential. Others come with warnings, usually along the lines of, “Here is the translation of this word into Japanese, but don’t use it because it’s rude.” Rarely is a more polite alternative suggested.
In the Japanese to English section, a fair few words don’t have translations, just explanations. Interested in the meaning of dokidoki? Well, according to my dictionary, “the basic meaning is to have the heart beat faster and faster with excitement or fear etc. and so translatable depending on the context.” A few entries bluntly say, “There is no real English equivalent.” Well, thanks for your help, dictionary-san; you are helpful as always.