现在分词用法？

Question

They had to edge their way along this， sometimes wading across shallow streams， or swimming across deep pools.
wading和swimming是现在分词吧？
可不可以写成sometimes they was wading across shallow streams or was swimming across deep pools.

Answer 1

1wading和swimming是现在分词
2想法可以，但是有点小的错误哦。
was 应该改为were ,因为they是复数。另外后面or 后面的 was去掉，即为：
sometimes they were wading across shallow streams or swimming across deep pools.
这个句子语法并没有什么错误，但意思上说不过去，sometime 为”有时“，说明不是正在进行的时态，故用现在分词wading和swimming欠妥，可以直接用过去时：
sometimes they waded across shallow streams or swam across deep pools.
希望可以解答您的疑惑