When programming, the computer will follow your instructions 100% literally. This means that it's not uncommon for a single semi-colon or a capital letter to break the flow of a program. It is important to imagine how a computer would process the instructions you are giving it. In this way you can find errors easier and be able to fix them
Key to thinking like a programmer https://www.youtube.com/watch?v=vrmKwQ-JPTA