You have unnecessary variables, when you should use sequence and loop:

from random import choice

sentence = [
    ("I", "The stupid cheeser", "He", "She", "The pirate personperson"),
    ("killed", "ate", "vomited" "ate", ":)'ed"),
    ("the stupid cheeser2",  "the moldy cheese", "the cow")
    ]

for values in sentence:
    print choice(values),
print '.'

You are not only one who got the idea for this kind of program, actually: http://www.daniweb.com/software-development/python/threads/32007/projects-for-the-beginner#post159482
The style of code does leave also lot to be desired as it is very old program. Here what I came up by playing with vegaseats' code:

  # goofy sentence generator

import random

def make_sentence(n, *parts):
    """return n random sentences"""
    for _ in range(n):
        yield ' '.join(random.choice(p) for p in parts).capitalize() + '.'

# break a typical sentence into 3 parts
# first part of a sentence (subject)

subject_ = """\
a drunken sailor
a giggling goose
the yearning youth
the obese ostrich
this mean mouse
the skinny sister""".splitlines()

# middle part of a sentence (action)
action_ = """\
jumps over
flies over
runs across
openly ogles
twice tastes
vomits on""".splitlines()

# ending part of a sentence (object)
object_ = """\
a rusty fence
the laughing cow
the weedcovered backyard
the timid trucker
the rancid old cheese
the jolly jelly""".splitlines()

print '-'*60

for item in make_sentence(3, subject_, action_, object_):
    print item
print '-'*60

"""
a typical result -->
A drunken sailor flies over the laughing cow.
The obese ostrich runs across the weedcovered backyard.
This mean mouse openly ogles the jolly jelly.
"""