Make sure that the landlord has given permission for sublet. It is easy to apply for the permission and it is usually granted. However, if the landlord has not given permission for sublet you might be evicted. It is the original tenant that is responsible for paying the rent to the landlord, make sure that he or she does that. If the rent is not payed you risk eviction as well. Finally, remember that you have the same rights as any other tenant. Tell the landlord about any problems, as long as the permission for sublet has been granted you have nothing to fear and the landlord cannot say no just because you have a sublet contract.