There are at least different 8 meanings. In your examples, they all mean "to make"/"to manage". 弄脏 = to make it dirty 弄丢 = to make it lost/manage in making it lost Other similar meanings like "to do", "to handle", "to fool with", "to mess with", "to toy with" depends on the context. FYI, here are a bit more common connotations of the word. 弄玉/璋 = toying with jade, (usually a name given to a daughter so that a brother may be born for her to play with). 弄权 = abuse of power. Here 弄 means illegitimate use. 弄点钱花 = unable to achieve/get some spare/pocket money 搔首弄姿 = to be dazzle. Here it means to show off. 弄琴 = playing a zither or a passage of music played on the zither. Depends on the context. 弄得人心惶惶 here it means "disturbing"

这两个词弄没有什么特殊的意思，就是帮助后面的词构成动词表达

这个例子里，“弄” 也可以换做“ 搞” 弄脏= 搞脏 弄丢= 搞丢 这里，“弄” 和“搞" 都有 fiddle with, play or manipulate 的意思。 弄脏： fiddle with something (carelessly or casually), so the result is that something is getting dirty. 弄丢： fiddle or play with something, and the result is that something got lost Hope this will help.

那么“搞”又是什么意思？搞是弄的意思。 这种解释只适合对针对母语者。 弄脏，比如一个打扫干净的房间，你随手把垃圾丢在地上，吃东西掉的满地渣子，把你的东西到处乱扔等等，于是屋子又变得很脏。所以弄本身是做的意思，比如我它弄完了，就是做完了的意思，上面提到的扔垃圾在地上等等，都是“做”，只不过做这些的结果造成了房子从干净变成了“脏”，这个脏，就你“做”出来的，也就是“弄脏”。 弄丢的弄也是一样，从没有丢，通过“做”，即你的某些行为造成了最后“丢”的结果，就叫弄丢。 而“搞”也有做的意思，我搞好了，就是我做好了意思。

“弄脏” 中的“弄”是“把………搞脏”的意思。 ”弄丢”中的“弄”是“把………丢失”的意思。 希望可以供你参考，谢谢！