Ok, there is a sentence that makes perfect grammatical sense. Nothing unusual there you may think. This sentence though contains the word 'had' in it 11 times in a row, yet it still makes sense.
Observe:
Ted and Fred had a grammar test. They were given the sentence: "by the time they got home they ______ dinner". They had two choices to fill the blank.
a) Had - they had dinner
b) Had had - they had had dinner.
Ted, while Fred had had 'had', had had 'had had'; 'had had' had had the teacher's approval.
And if you get that you deserve a coconut.