Please make sure the goods are delivered on time. Some however, are always used in the singular. E.g. advice, poetry, stationery, scenery, machinery, mischief, luggage, baggage, fuel, hair, information, rice, furniture etc. Your hair is very beautiful. There is a lot of luggage.
Abstract nouns have no plurals.
E.g. Honesty is the best policy. Material nouns are not used in the plural. There is a lot of copper in this region. Ram and Shyam are good friend. Love are everywhere.