—I shall give it to you since you have asked me for it very politely.
—We shall go to walk in the park rather than in the crowded streets.
—I shall give you that toy although I should have preferred to let you have a beautiful book.
—You may promise to go and visit him to-morrow provided you keep your promise.
The children are permitted to work at their various occupations in complete freedom. (The Lenox School, Montessori Elementary Class, New York.)
Permutations
The removal of the conjunction destroys the relationship between the words, and this brings out its function in the sentence:
Put away the pen and the ink-stand.
Put away the pen the ink-stand.
Put away the pen or the ink-stand.
Put away the pen the ink-stand.
You could write with your left hand if you touched the letters with that hand.
You could write with your left hand you touched the letters with that hand.