is true that in old japanese writing d'ont exist dakuten and handakuten?if is true how distinguish between -hu and -pu,-ka and -da, etc(huuhu and puupu is writing with the same hiragana and means 2 different things,another example hokai,hodai),how old japanese know when pronnounce -hu and when -pu.I d'ont understand ,can someone explain me? (sorry for my english)

I don't really know about old Japanese writing, but in terms of having two words spelled the same and pronounced differently, this occurs in English all the time:

I *read* a book yesterday. Did you *read* a book yesterday?

I stood on the *bow* of the ship, holding a *bow* and arrow.

Every summer, John *sows* the field with seeds, but then the *sows* come along and eat them.


With context (i.e. the surrounding words and grammar) we can usually work out easily which pronunciation/meaning to allocate to the group of letters we are reading.

In modern Japanese, the は character is similar: when we read we simply know from context whether it is the particle pronounced WA or a word pronounced HA (tooth, teeth, leaf, etc) or, for that matter, simply part of the spelling of a longer word.

It was distinguished through context. I still have to read things without dakuten (or punctuation) for my dissertation research, and once you get used to it you can mentally fill them in just based on context. But there are times when you don't know which one it is.