Ask the children to think of a four-letter animal, place or thing that they like. Have them write this word vertically down the left margin of their piece of paper.
Have them describe the place, thing or animal with a short sentence beginning with the first letter of the word they have written vertically on the page. Have them write the sentence on the line next to the first letter, so the first letter of the word becomes the first letter of their sentence as well.
Ask what this thing, animal or place does -- some habit or function. Have them describe it in a sentence beginning with the second letter of the vertical word. Have them write the sentence on the line next to the second letter of the word, so the letter becomes the beginning of the sentence they wrote.
Brainstorm with the children how this thing, animal or place is usually thought about by others. Have them compose a sentence describing this commonplace perception that begins with the third letter of the vertical word. Using that letter as the first of their sentence, have them write the sentence onto the same line as the letter.
Ask the children to think of something that most people don't know about this animal, place or thing. Have them compose a sentence about this new fact that begins with the fourth letter of the vertical word. Have them write this sentence on the same line as the fourth, vertical letter.