I am copying multiple lines from different parts.
I can for example do
to copy the 3 next lines.
Then I would like to scroll a bit and add 5 more lines:
and so on. At the end, I want to paste all lines (in this case 8)
You can append to the named registers
"z, in which case you use the lowercase versions of the registers to overwrite/replace their contents and the uppercase version to append to their contents.
So you can use
3"ayy) for the initial yank of 3 lines, then
5"Ayy) to append the 5 next lines to that same register, which you can then put using
"Ap also works.)
:help "a for details.
A neat trick to use when appending to named registers is that you can use the
q command (which records macros) to empty the registers. For example,
qaq will clear register
"a. (It starts recording a macro into register
"a, and then the second
q ends the recording right away.) By clearing the register first, you can then use the uppercase register for appending on the first yank, which can be useful if you're using a repeated command such as a macro or a
:g command to yank multiple lines.