List of top English Grammar Questions on Error Spotting

Choose the part of the following sentence that contains an error :
The most important feature of our products are that they are all created by hand.

Choose the correct question tag ?

Choose the part of the following sentence that contains an error :
Ranjeeta does not usually prefer staying at cottages, but last winter she spent few days in one.

Choose the part of the following sentence that contains an error :
If a company sends it employees abroad to work for a foreign client, they pays them a daily allowance.

Choose the part of the following sentence that contains an error :
It is the quarter to ten by my watch.