If your child is feeling sad, try playing with him. It will remind him that you love and care about him, and it might help take his mind off his problems.  If your child still plays with toys, then join him in playing with his favorites. If he's moved on to video games, try joining him for a few levels. Make sure your child has access to toys/activities that engage the senses. Some experts have found that playing with tactile materials, like clay, play dough, sand, rice, and even water can help sad children work through their emotions. Depending on your child's age, gender, and personality, he or she may be interested in a number of things. No matter what your child is interested in, try engaging with him in that interest. It will help him connect with you, and it might open the door to deeper, more meaningful conversations about other aspects of his life.  If your kid likes comics, ask him about his favorites, or ask if you can borrow one of the comics he likes the most. If your child is interested in cartoons or TV shows, ask if you can watch with him. This can give you a better idea of his sense of humor at his current age, which might make it easier to cheer him up when he's sad. If your child is into sports, watch a game with him, or buy tickets to catch a game in your hometown. No matter what your child is interested in, you should develop some degree of interest in those things too. It will help you bond, and you'll know how to engage with him the next time he's feeling down. This may not interest all children, but many kids want to act out or play pretend with issues they're interested in. This might be a current family issue, like a recent death, or it might be something your child is exposed to but doesn't fully understand, like church services or job responsibilities.  Playing pretend is a great way for children to explore a concept in a safe, inquisitive environment. Make sure you're supportive of your child's choice to act out what's going on. You may feel a little upset if your child is playing...

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Write a summary of the previous text in Vietnamese:
Chơi đùa cùng trẻ. Quan tâm đến những điều khiến trẻ thích thú. Hãy để trẻ diễn lại những phiền muộn đang gặp phải. Đi bộ hoặc đi xe đạp cùng nhau. Cho trẻ có thời gian ở một mình. Ôm trẻ. Gây ngạc nhiên cho trẻ bằng một số niềm vui. Thử giúp trẻ sẵn sàng đi ngủ.