Emergent writers may not be able to record words. Their writing may consist of a string of letters that stand for words. They will gradually refine this process and be able to record more of the sounds that they hear. Children may need help to realize that written English is broken down into words. Encourage them to use finger spaces between words when they are writing.
Children can see the teacher model how phonetic rules and spelling conventions are applied.
Start with the basics. This modelling is very important. It will be a capital because it is the word starting your sentence. You can point out that the word needs a vowel. In other words you are providing the information that they don't have yet, in chunks that they can handle.