Recently, someone hired me to translate foreign books through the Internet, but he couldn't provide the original Chinese copyright grant document. If I translate them, will it be regarded as infringement? Translation right is one of the property rights in copyright, which can only be carried out with the permission of the copyright owner.

Now it's equivalent to Party B hiring you as an interpreter. The agreement between you and Party B can be written as follows: Party B guarantees whether the translated works are licensed or not, otherwise, Party B will bear the tort liability and the contract will be terminated.