Learn how to correct student's spoken errors
It's important that you correct students mistakes. However, you don't want to correct all of their mistakes. Constant correction will demotivate them. Fear of making mistakes can be a big inhibitor, especially for adolescents and above. You want them to feel comfortable and not afraid.
The mistakes that you do want to correct are the ones that relate to the lesson of the day. Correct the mistakes which are part of what you are teaching them on that day. So if a student mispronounces a word, say it correctly and have them repeat after you. Some students will feel embarrassed when making a mistake and being singled out, so then you can have them and the whole class repeat the word together. This takes the eyes and pressure off of them.
Sometimes you don't have to say the correct word after they have made a mistake. You can just say what they have said and they will just correct themselves.