Plural humor

I've long mused that the only languages that I know that add an 's' to indicate a plural noun are English, French, and Spanish. Other languages that I've encountered use other final sounds or inflection. Inflection is the changing of a vowel sound, like one alumnus or many alumni.

English however uses inflection also. Is this a holdover from its Germanic origin?

For example, we have goose and geese, mouse and mice. Does this last mean that the plural of spouse is spice? When I mentioned this to my wife, I added I really think the plural of spouse is trouble.