I´ve made this worksheet for beginners. It shows where to put an A before a consonant and AN before a vowel, but also the exceptions (because we know this rule isn´t really exclusive.) I hope you like it.
I'm half of a teaching pair in the UK. I found this site so useful so I've been adding more of my own worksheets. I hope you all like them. If you have any ideas or requests please just let me know. Cheers. Em