What happens for me is, if I tap the query text in the input at the top of the results page, it is briefly selected, then an insertion point appears near where I tapped. I can drag that to the end and then start typing.

This behavior might vary between devices and versions, I'm using Gingerbread on an HTC device.

I meant if I go to Google.com then on the webpage search for something I can't edit on webpage like a desktop browser I tried it in Google chrome and it works

I see now, I wasn't using a long enough query. If any of the query is beyond the search box width, the insertion point cannot be dragged there; it seems to stop working where the gray circle-x icon appears in the search box.

you got it I just thought I would share what I've seen hopefully it can be fixed