Knowing the letter shapes and sounds associated with them is important for learning the written language, and going in with at least some of this knowledge can help your child succeed at learning how to read. While a child doesn't have to know every letter in the alphabet, it's best if he can recognize common letters, or the letters present in his own name. Use flash cards and refrigerator letter magnets to help your child with this important step.
Being able to count and recognize numbers is another important thing to know for a child who's entering kindergarten. Most children of this age grasp counting and are able to use their fingers to indicate what they mean, but sometimes they struggle with knowing which written number they mean. Practice counting by teaching your child roman numerals, and use flash cards to help him learn the written number.
Even schools that have an ideal student to teacher ratio don't have enough teachers to spare one when a child needs to use the restroom. Your child needs to be able to go to the bathroom on his own, including all of the undressing and dressing that would need to be done to use the restroom. The child will also need to be able to put on his own coat and button or zip it.
Some children will always have difficulty with patience, but by the time he's entering kindergarten, he should be able to sit and listen to a story, song or a lesson for a period of time. He also should be able to listen to a story or song without interrupting. Practice this at home during story time, or take him to public story times at a public library. There will be other children present and it will be easier for your child to understand that disrupting the story disrupts it for everybody.
Time can be difficult for young children to grasp. Buy play clock faces and work with your child to understand how time passes, and use a digital clock so that the child can count the time off as it goes by. The child probably won't fully understand it, but he will start to grasp what fifteen minutes or an hour might mean. Understanding time will help him to learn the patience to sit still for a period of time.
Your child should be able to trace basic shapes and draw basic humanoid figures by this time in development. Often your child can learn this if you give him the drawing implements and let him try, but if your child seems to have trouble, draw an example stick man for him to imitate.
Recognizing colors will go hand-in-hand with drawing on a regular basis. Your child should be able to know the difference between black, white, and some of the primary and secondary colors. Your child will label the color closest to the vocabulary that he possesses, so a very light green chair might be called yellow and a dark orange chair would be called red. This is normal, as long as he's recognizing the color group. If he seems to have difficulty distinguishing between colors that are opposite each other on the color wheel, such as green and red, this can indicate color blindness.
A child should be able to imagine that he's doing something that he isn't, such as working on a pirate ship. This is called imaginary play and is a milestone that should occur at or earlier than five years of age. Children of this age do have a problem telling between fantasy and reality, and that's completely normal; your child still should be having play that involves things or people that aren't present.
When you're putting your child under the care of another person, he should be able to tell that the other person is in charge of him. This includes following commands that a teacher might issue. This is something that you'll have to explain to your child, and maybe practice with a friend or babysitter.
There are certain activities an otherwise healthy kindergartner should be coordinated enough to do. While a child of that age is still learning fine motor skills, he should be able to bounce a ball, jump, and stand on one leg for a short period of time. Many will be able to do somersaults as well. This is the kind of activity your child should practice outside, and having other children present may help. Your child may seem frustrated with himself when he falls or can't do something, but this is normal and it just means that his body hasn't caught up with what he believes he can do.
Every child is different and learns at a different pace. Being prepared for kindergarten is really helpful, but your child does have plenty of time to catch up. Being behind doesn't even mean anything is wrong, it just means that your child is a little behind. If you're concerned that your child may be facing developmental issues, your school will be able to put you into contact with an expert who can diagnose any learning or developmental disorder.