Why is this the answer?

The answer is clock because this clever riddle uses everyday words in a tricky way to describe something we rely on all the time. Let us break down the clues one by one to see how they all point to the clock. The first clue is: This thing runs but cannot walk. When you check a watch or a wall clock, you know it is working because its hands are moving. We use the word runs to mean that the clock is operating correctly and counting the minutes and hours. It is constantly moving forward, or running, even though it stays right where it is, on the wall or on a table. It does not have feet or legs, so it can never truly walk. The next part says: sometimes sings but never talks. While a clock cannot talk to you like a person, many clocks are designed to make noise. Think about an alarm clock that buzzes or plays music to wake you up. That noise is like a song or a chime. Or imagine a grandfather clock in a hallway that makes a deep, beautiful sound on the hour. These sounds are its special singing, but it will never have a real conversation with you. Then the riddle tells us it Lacks arms, has hands. This is a playful clue. A person has arms and hands, but a clock has no arms. However, it does have hands that show the time. There is a small hand for the hours and a big hand for the minutes. Sometimes there is a third, quick hand for the seconds. These hands are what make the clock useful, as they point to the numbers on its face. Lastly, it says it lacks a head but has a face. The flat, front part of the clock, where all the numbers and the hands are found, is called the clock's face. This face is where you look to see the time of day. It looks a little bit like a friendly, round face, but of course, it does not have a head or a brain inside to think. All these surprising details come together to describe the same important object that helps everyone keep track of time and know when it is time to go to school or when it is time for recess. That is why the clock is the perfect solution to this excellent riddle.