Single quotes and double quotes can both be used to declare strings in Python. You can even use triple-double quotes! Learn when to use each in this lesson as well as variable substitution in strings.

foo = 'What is up'

foo = 'What\'s up'

foo = "What's up"

foo = """ what's up
man
!"""

color = 'red'
thing = 'book'
print('this is {0} {1}'.format(color, thing))