▲still less 属固定搭配，意思是“更不用说”，其后可接名词、代词、介词短语、动词或句子。如：

I never talked about it, still less about her. 我从来没说起过这事，更没有提起过她。

He can't read English; still less can he teach it. 他看都看不懂英语, 更不用说教了。

They are always short of water to drink, still less to bathe in. 他们的饮用水一直短缺，更别提洗澡水了。

But we must not think of Chekhov as a leftist, still less a revolutionary. 但是我们绝不应把契科夫看成是个左派人物，他更不是革命者。

▲这样用的 still less 也可说成 much less, even less。如：

She can't finish her own work in time, even less help others. 她连自己的工作都不能及时完成,更不用说帮助别人了。（接动词）

He can hardly spare me a minute, much less an hour. 他连一分钟都不能为我腾出来，更不用说一小时了。（接名词）

▲更详细的用法说，请参见：http://www.yygrammar.com/Article/201405/3620.html