The trickiest language

We'll begin with box, and the plural is boxes, 

But the plural of ox should be oxen, not oxes. 

Then one fowl is goose, but two are called geese, 

Yet the plural of moose should never be meese. 

You may find a lone mouse or a whole lot of mice, 

But the plural of house is houses, not hice. 

If the plural of man is always called men, 

Why shouldn't the plural of pan be pen? 

The cow in the plural may be cows or kine, 

But the plural of vow is vows, not vine. 

And I speak of a foot, and you show me your feet, 

But I give a boot... would a pair be beet?

If one is a tooth, and a whole set is teeth,

Why shouldn't the plural of booth be beeth?

If the singular is this, and the plural is these,

Why shouldn't the plural of kiss be kese?

Then one may be that, and three be those,

Yet the plural of hat would never be hose.

We speak of a brother, and also of brethren,

But though we say mother, we never say methren.

The masculine pronouns are he, his and him,

But imagine the feminine she, shis, and shim.

So our English, I think you will agree,

Is the trickiest language you ever did see.

(Thanks, Thomas)