On macbook keyboard, there is only one ctrl key on the left. I am so used to for half page down using the right ctrl key that it is driving me crazy. Any way to remap the left key to ctrl?
While (post-experimentation and reading) I have found no way to remap
<Left> to send Ctrl, I can at least point you in two different directions:
You can "simulate" this with some mappings for common tasks, like
nnoremap <silent> <Left>d <C-d>
The downside is that you'll need to do this for any and all commands you want to map.
While off-topic here, the internet and other stackexchange sites have lots of information on changing your keyboard layout (especially for modifier keys).
For example, I use CapsLock to send Ctrl: it saves me a lot of pinky strain.