么 (ma) is a variant character for the question particle 吗 (ma), used at the end of yes-no questions in informal or non-standard writing. In standard Mandarin, the particle is normally written as 吗, but 么 appears occasionally in casual text and certain dialects. Note that 么 also has a different reading (me) in words like 什么 (shénme, 'what') and 怎么 (zěnme, 'how'); this entry covers the ma reading specifically.