take something on和take someone on有何分別？

二者意義繁多，僅選其中一兩種解釋：
(a)take something on即undertake or agree to do a task，指「擔任」、「負擔」，例如：

I'm very busy, so I don't want to take on any more work.

我很忙，故不想再負擔更多工作。
(b)take someone on即employ，指「僱用」，例如：

The company took on 30 extra workers last month.

該公司上月額外僱了30名工人。
(c)又意為contend with as an opponent，指「較量」，例如：

The workers are determined to take on the government in this dispute.

該批工人決心在爭端中與政府較量一番。