These structures, coming from French, are often considered inelegant and normatively undesirable. However, in certain areas (especially the economic, the administrative and the journalistic) they have reached a notable extension, due to their brevity. Although its use is admitted in certain contexts (amount to be entered, issues to be addressed, problems to be solved, etc.), it should not be forgotten that on many occasions its use is superfluous and, therefore, it is preferable to avoid it.
When greater ¾form coming from the Latin comparative maior¾ it is used with true comparative value, that is, with the meaning of ‘that exceeds something else in size, quantity, quality or intensity’ and, referring to a person, ‘that exceeds another in age ‘, its combination with more is incorrect; Thus, The bathroom is not bigger than the kitchen or My brother Pedro is older than you are incorrect sentences for The bathroom is not bigger / bigger than the kitchen or My brother Pedro is older than you.
But older has, within the field of age, senses in which it functions, not as a comparative form of great, but as a true adjective in a positive degree and, in those cases, like the rest of the adjectives, admits its combination with marks of degree as more.
When it is opposed to small and means “of no small age.” A child may say I am older, simply wanting to express that they no longer consider themselves small. With this greater sense, it does admit its combination with grade marks, such as more, very or so: When you are older, we will buy you a bicycle; Look how old and still with a pacifier!
When used in the more precise sense of ‘adult’: When I grow up, I will leave home.
The existence of these non-comparative uses of the adjective older makes it possible and equally correct, although of slightly different meaning, the sentences When you are older (= when you are an adult), you can wear that dress and When you are older (= when you have more age than you are now), you can wear that dress.
When it means ‘elderly’: On buses you have to give up the seat to older people. Also in this older case admits its combination with grade marks: I found your father tired, older, almost an old man.
In constructions made up of two nouns that constitute a lexical unit, in which the second of them modifies the first as if it were an adjective, normally only the first noun is marked with the plural: rush hours, limpet pumps, skorts, dorm towns, show flats, sleeper cars, frogmen, child prodigies, bombshell news, sofa beds, etc.