Are these sentences right

[silviasabater_2000]

Hi there,

I'm not sure if these sentences are grammatically right and if they make sense. Can someone help me please?

Thanks!

She alerted them of the storm
I explained in a conference that I had found rock paintings where were represented a group of prehistoric people swimming around a strange kind of whales. This fact proves the relationship between man and animals at that time.
Those ancient humans usually depicted odd situations such as them hunting enormous animals.
It is interesting to see the first way in which pre-historic men showed feelings, wishes and fears.
I like rock paintings because I think they represent the beginning of history.
From my point of view, these rock paintings were hard to be painted.

[David L.]

She alerted them to the storm
I explained in a conference that I had found rock paintings where were represented a group of prehistoric people swimming around a strange kind of whale. This fact proves the relationship between man and animals at that time.

'whale' in the singular, no matter how many 'whales' were there, because you are referring to 'one kind of whale" 'one species of whale'. As you can then see, the reader does not know whether there was one whale or more than one. This is then one of those situations in English where, if this point is important, you would have to rephrase the sentence eg
'...swimming around strange-looking whales.'

Those ancient humans usually depicted odd situations, such as them hunting enormous animals.

It is interesting to see the first manner in which pre-historic man showed feelings, wishes and fears.

better : It is interesting to see the way in which pre-historic man first showed feelings, wishes and fears.

I like rock paintings because I think they represent the beginning of history.
From my point of view, these rock paintings must have been hard to paint.