I am pretty sure you have an amazon sword because the venation in your plant is similar to the amazon sword. The Java fern has much more distinct venation especially in the stem area of the leaf. Also, some pictures of the java fern I looked at had ripples in the edge of the leaf. I hope this helps. If you need help finding information about the amazon sword and care for it, please let me know. 
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Phishie
"An ounce of prevention is worth a pound of cure."


