71. I can’t take on any more responsibilities.

　　72. I can’t do what you’re asking.

　　73. I can help you out next weekend instead.

　　74. Let me think about that.

　　75. Here’s what will work for me.

　　76. Can I get back to you?

　　77. That doesn’t work for me.

　　78. I’m sorry I’m busy.

　　79. Thanks for thinking of me. I really wish I could.

　　80. I’d love to, but I’m already overcommitted.

　　81. Unfortunately, that’s not something I can do at this time.

　　82. No thanks.

　　83. I’m already booked.

　　84. Maybe next time.

　　85. I don’t think I’m the right person to help with that.

　　86. Sorry I can’t help you this time.

　　87. Sounds fun, but I’m not available.

　　88. That’s not going to work for me.

　　89. Sorry, no can do.

　　(《牛津英语辞典》对no can do这句貌似中式英文的口语的解释是：It is not possible, it cannot be done; ‘I can't do it.’)

　　90. How about no?

　　91. Not in this lifetime.

　　92. Listen, I have to get going, but thanks for asking.

　　93. Sounds tempting, but I’ll have to pass.

　　94. It’s not my thing.

　　95. My body says yes, but my heart says no.

　　96. I have other plans tonight.

　　97. Let me check my calendar.

　　98. Are you able to better that offer?

　　99. Yes, with these conditions.