This dictionary is worth buying for at least three reasons. First, it contains simply-to-understand explanations of both words and expressions currently used in English speaking countries. Furthermore, it usually distinguish between a formal and an informal use of its entries, as well as among American, Australian, and British English. Finally, it provides English learners with some very clear examples of how to use every word and expression properly. Yet the Collins Cobuild has some blemish, too. For instance, I think the Editorial Team was in a hurry, when they decided the definition of "summary": "(Count noun.) You use 'in summary' to indicate that what you are about to say is a summary of what has just been said." This definition is pointless. In order to find what a "summary" is, we must look at other entries -- e.g., "to recapitulate": "(Verb.) ...You can say that you are going to 'recapitulate' the main points of an explanation ...when you want to draw attention to the fact that you are going to repeat the most important points as a summary." But if we can already suppose to find the meaning of "summary" by looking at "to recapitulate", perhaps we do not need to search that word in a dictionary! For this reason, I think that (at present) the Collins Cobuild Dictionary cannot be awarded five crowns, albeit (generally speaking) it is a very good dictionary.