Fǎn / guò / lái / shuō / rúguǒ / méiyǒu / tā / de / bāngzhù / wǒmen / hěn / nán / wánchéng / rènwu

反过来说，如果没有他的帮助，我们很难完成任务。

Conversely, without his help, it would be difficult for us to complete the task.