New York: Even before they can read, children as young as three years of age can understand how a written word is different than a simple drawing, and the ability to make this distinction could signal if your toddler is ready to learn to read, a new study has found. Most children do not begin formal instruction in reading and writing until they turn five and enter kindergarten, but these findings suggest that children as young as three may be tested to see how well their understanding of basic language concepts is progressing. "Our results show that children have some knowledge about the fundamental properties of writing from a surprisingly early age," said study co-author Rebecca Treiman from Washington University in St. Louis in the US. "Based on the results, it may be possible to determine at an early age, which children are progressing well in the learning of emergent literacy skills and which children may need extra attention," Treiman added. The study was based on two experiments with 114 children ages three to five years who had not yet received any formal instruction in reading or writing. The children were tested to see how well they understood that a written word, such as dog, has one specific pronunciation ("dog") as compared with a simple drawing of a dog, which could be correctly labeled as the image of a dog, a puppy or even a pet named Spot. In the first test, researchers read the written word "dog" to the children. Later, when a puppet employed in the experiment and read the word "dog" as "puppy," many children picked up on the mistake. In a similar task with drawings, children were more likely to say that the puppet was correct in using the alternative label. The different results in the writing and drawing conditions indicated that even young pre-readers have some understanding that a written word stands for one specific linguistic unit in a way that a drawing does not. The study was published in the journal Child Development.