number 1 singular to plural

in this presentation you will check how you can change a word from singular to plural. how to use a or an in a singular way.....
step 1. check the presentation
step 2. write in your notebook the words that you will have at the end of the presentation
step 3. write the prural way then
step 4. present it to your teacher (send an e-mail to colmexprepa.betzabell@gmail.com)
step 5. you will have only 2 day after you see this presentation
step 6. if you present 10 from 20 activities, you won't present an exam, you will be evaluated with those