at the moment 的意思是“现在”“此刻”,常与一般现在时或现在完成时连用.例如：I have got enough to do at the moment.
但是,at the moment 有时也作“当时”讲,用于过去时态.例如：
I didn't buy that book,because I had no money on me at the moment.
2.for the moment意为“暂时”.如:
She is out,so you may use her typewriter for the moment.
她出去了,你可以暂时使用她的打字机.
3.in a moment 意为“立刻”.如:
I'll join you in the discussion in a moment.
我一会儿和你们一起讨论.
4.for a moment意为“一会儿”.如:
I had to think for a moment before I remembered his name.
我想了一会儿才记起他的名字.