"Oh dear, there is a lion in your house again."
Translation:Obh obh, tha leòmhann anns an taigh agad a-rithist.
Yes, I keep a lion in my house to keep the bears away. You have probably seen the other sentence
Now you know why.
Actually they have a courtyard in Stirling Castle where they used to keep lions. It was empty last time I visited. I suspect the space would not meet modern welfare regulations for lions as it is not very big.
None, except that the 'there is' construction is regarded as more natural English. The rule for translating into Gaelic (if you want one) is that you should not translate the there at the beginning of the sentence if there is another bit saying where the thing is as well (in the house).