A snippet for Xmodmap that will teach you to use the correct shift keys.

.Xmodmap

remove shift = Shift_R
remove lock = Caps_Lock
remove mod5 = Mode_switch

add control = Caps_Lock
add mod3 = Mode_switch

keysym Shift_R = Mode_switch


keycode  10 = 1 1 exclam exclam
keycode  11 = 2 2 at at
keycode  12 = 3 3 numbersign numbersign
keycode  13 = 4 4 dollar dollar
keycode  14 = 5 5 percent percent
keycode  15 = 6 asciicircum 6 asciicircum
keycode  16 = 7 ampersand 7 ampersand
keycode  17 = 8 asterisk 8 asterisk
keycode  18 = 9 parenleft 9 parenleft
keycode  19 = 0 parenright 0 parenright
keycode  20 = minus underscore minus underscore
keycode  21 = equal plus equal plus

keycode  24 = q q Q Q
keycode  25 = w w W W
keycode  26 = e e E E
keycode  27 = r r R R
keycode  28 = t t T T
keycode  29 = y Y y Y
keycode  30 = u U u U
keycode  31 = i I i I
keycode  32 = o O o O
keycode  33 = p P p P
keycode  34 = bracketleft braceleft bracketleft braceleft
keycode  35 = bracketright braceright bracketright braceright

keycode  38 = a a A A
keycode  39 = s s S S
keycode  40 = d d D D
keycode  41 = f f F F
keycode  42 = g g G G
keycode  43 = h H h H
keycode  44 = j J j J
keycode  45 = k K k K
keycode  46 = l L l L
keycode  47 = semicolon colon semicolon colon
keycode  48 = apostrophe quotedbl apostrophe quotedbl
keycode  49 = grave grave asciitilde asciitilde
keycode  51 = backslash bar backslash bar

keycode  52 = z z Z Z
keycode  53 = x x X X
keycode  54 = c c C C
keycode  55 = v v V V
keycode  56 = b b B B
keycode  57 = n N n N
keycode  58 = m M m M
keycode  59 = comma less comma less
keycode  60 = period greater period greater
keycode  61 = slash question slash question