The plural in English is usually made
By adding an 's', so don't be afraid
Of making this sound so that it can be heard
At the end of the plural form of a word

Then there will be no doubt in anyone's mind
Whether your meaning is of the singular or plural kind
An extra syllable is needed when patch becomes patches
And take note that the plural of batch is batches

Of course there are always exceptions to every rule
The fish that swim around in a school
Are still just fish, they don't become fishes
But the plural of dish will always be dishes

The plural of goose is, as we all know, geese
Although the plural of moose is definitely not meese
One mouse, but a plague of them would be called mice
Though to call houses hice is something for which I do not give advice

Hypothesis in plural form translates to hypotheses
And parenthesis, of course, becomes parentheses
But your garden variety of plurals, just stick an 's' on
Next week we'll talk about the 's' for possession

(Sydney, Australia - 2006)

Alessandra Liverani

http://www.poemhunter.com/poem/making-plurals-in-english-humour/