1. I think last weeks exam was not difficult.
2. I don't think Mie was mean as a child.
3. I don't think Mai received a letter.
My answers:
1. せんしゅうのしけんはむずかしくなかったとおもいます。
2. みえさんはこどものといいじわるじゃなかったとおもいます。
3. まいさんはてがみをもらわなかったとおもいます。
Also, how would I say:
' I don't think Mai received a letter from Mari '
Thanks!