Here you have a very common mistake, especially for Spanish students. You should go to this link because it's a great explanation (in Spanish) and you can do some examples to practise. Click here
If you want to practise a bit further, go to these pages:
You shouldn't have problems any more if you do all these exercises but to finish with you can see common expressions with "other" in another page. It could be useful and I think it's worth a visit. Click here
See you
