Why English is so difficult to learn...

This is from Greater Things.

We polish the Polish furniture.

He could lead if he would get the lead out.

A farm can produce produce.

The dump was so full it had to refuse refuse.

The soldier decided to desert in the desert.

The present is a good time to present the present to the President.

At the Army base, a bass was painted on the head of a bass drum.

The dove dove into the bushes.
I did not object to the object.

The insurance for the invalid was invalid.

The bandage was wound around the wound.

There was a row among the oarsmen about how to row.

They were too close to the door to close it.

The buck does funny things when the does are present.

They sent a sewer down to stitch the tear in the sewer line.

To help with planting, the farmer taught his sow to sow.

The wind was too strong to wind the sail.

After a number of Novocaine injections, my jaw got number.

I shed a tear when I saw the tear in my clothes.

I had to subject the subject to a series of tests.

How can I intimate this to my most intimate friend?

I spent last evening evening out a pile of dirt.

Also:
There is no egg in eggplant, nor ham in hamburger; neither apple or pine in pineapple. And while no one knows what is in a hotdog, you can be pretty sure it isn't canine. English muffins were not invented in England nor French fries in France. Sweetmeats are candies, while sweetbreads, which aren't sweet, are meat.
We take English for granted. But if we explore its paradoxes, we find that quicksand can work slowly, boxing rings are square, and guinea pig is neither from Guinea nor is it a pig.
And why is it that writers write, but fingers don't fing, grocers don't groce, and hammers don't ham? If the plural of tooth is teeth, why isn't plural of booth, beeth?  One goose, 2 geese. So one moose, two meese? Is cheese the plural of choose? One mouse, 2 mice. One louse, 2 lice.  One house, 2 hice? If teachers taught, why didn't preachers praught?
If a vegetarian eats vegetables, what does a humanitarian eat? Why do people recite at a play, and play at a recital?  Ship by truck or car and send cargo by ship?  Have noses that run and feet that smell? Park on driveways and drive on parkways?
How can a slim chance and a fat chance be the same, while a wise man and a wise guy are opposites? How can the weather be hot as heck one day and cold as heck another?
If a house burns up, it burns down.  You fill in a form by filling it out and an alarm clock goes off by going on.  You get in and out of a car, yet you get on and off a bus.  When the stars are out, they are visible, but when the lights are out, they are invisible.
And why, when I wind up my watch, I start it, but when I wind up this essay, I end it?
English is a weird language ... it doesn't know if it is coming or going!!!
War never determines who's right.  War only determines who's left. 

Going a little further, turkeys aren't from Turkey and buffaloes aren't found in Buffalo (except maybe at the zoo). Why is the plural of bison "bison", but buffalo has a plural form? Why doesn't a near miss actually mean a hit? Why is insane the opposite of sane and indecent the opposite of decent; but inflammable is the same as flammable?

Ahh, so many conundrums with the English language... So little time.