All we are planning to do is watch a couple of DVDs.请问为什么这里用watch 不用to watch 或是 is watching?

We are planning ＿（have）an English party. We are planning to______our house______(请人粉刷)next month. All we are planning to do is watch a couple of DVDs.请问为什么这里用watch 不用to watch 或是 is watching? we are all with We are all mad Are we all here? we are all shanghai we are all small. we are all Chinese,we all are Chinese哪个对? we are all ultimately we are all ultimately alone We are all happy等于 We are all ( ) 同义句 We all are和We are all有什么不同 we are all always friend We are all different ages We are all student We all are student请问是We are all student 还是 We all are student 英语翻译we are planning to conduct the review regarding the projects below in china. We are planning to ()a party to celebrate Tina's good news（make/throw/do) we are planning to go on a t____ to EXPO 2010 shanghai during the coming holidays.