Words that sound alike or look alike (moral/morale) often confuse people, especially those using spell checkers. This lengthy list of commonly confused words with simple definitions will help you decide which spelling fits your sentence.
Please note: When I say "lengthy" I really, really mean LENGTHY.

accept to receive
except with the exclusion of

advice recommendation (noun)
advise to recommend (verb)

adverse unfavorable
averse opposed to affect to influence (verb); emotional response (noun) effect result (noun); to cause (verb)

aisle space between rows
isle island

allude to make indirect reference to
elude to avoid

allusion indirect reference
illusion false idea, misleading appearance already by this time already fully prepared

altar sacred platform or place
alter to change

altogether thoroughly
all together everyone/everything in one place

a lot a quantity; many of something
allot to divide or portion out

angel supernatural being, good person
angle shape made by joining 2 straight lines

are plural form of "to be"
our plural form of "my"

accent pronunciation common to a region
ascent the act of rising or climbing
assent consent, agreement

assistance help
assistants helpers

bare nude, unadorned
bear to carry; an animal

beside close to; next to
besides except for; in addition

boar a wild male pig
bore to drill a hole through

board piece of wood
bored uninterested

born brought into life
borne past participle of "to bear" (carry)

breath air taken in (noun)
breathe to take in air (verb)

brake device for stopping
break destroy; make into pieces

buy to purchase
by next to; through the agency of

canvas heavy cloth
canvass to take a survey; a survey

capital major city
capitol government building

choose to pick
chose past tense of "to choose"

clothes garments
cloths pieces of fabric

coarse rough
course path; series of lectures

complement something that completes
compliment praise, flattery

conscience sense of morality
conscious awake, aware

corps regulated group
corpse dead body

council governing body
counsel advice; to give advice

dairy place where milk products are processed
diary personal journal

descent downward movement
dissent disagreement

dessert final, sweet course in a meal
desert to abandon; dry, sandy area

device a plan; a tool or utensil
devise to create

discreet modest, prudent behavior
discrete a separate thing, distinct

do a verb indicating performance or execution of a task
dew water droplets condensed from air
due as a result of

dominant commanding, controlling
dominate to control

die to lose life; one of a pair of dice
dye to change or add color

dyeing changing or adding color
dying losing life

elicit to draw out
illicit illegal, forbidden

eminent prominent
imminent about to happen

envelop to surround (verb)
envelope container for a letter (noun)

everyday routine, commonplace, ordinary (adj.)
every day each day, succession (adj. + noun)

fair light skinned; just, honest; a carnival
fare money for transportation; food

farther at a greater(measurable) distance
further in greater(non-measurable) depth

formally conventionally, with ceremony
formerly previously

forth forward
fourth number four in a list

gorilla animal in ape family
guerrilla soldier specializing in surprise attacks

hear to sense sound by ear
here in this place

heard past tense of "to hear"
herd group of animals

hoard a hidden fund or supply, a cache
horde a large group or crowd, swarm

hole opening
whole complete; an entire thing

human relating to the species homo sapiens
humane compassionate

its possessive form of "it"
it's contraction for "it is"

knew past tense of "know"
new fresh, not yet old

know to comprehend
no negative

later after a time
latter second one of two things

lead heavy metal substance; to guide
led past tense of "to lead"

lessen to decrease
lesson something learned and/or taught

lightning storm-related electricity
lightening making lighter

loose unbound, not tightly fastened
lose to misplace

maybe perhaps (adv.)
may be might be (verb)

meat animal flesh
meet to encounter
mete to measure; to distribute

metal a hard organic substance
medal a flat disk stamped with a design
mettle courage, spirit, energy

miner a worker in a mine
minor underage person (noun); less important (adj.)

moral distinguishing right from wrong; lesson of a fable or story
morale attitude or outlook usually of a group

passed past tense of "to pass"
past at a previous time

patience putting up with annoyances
patients people under medical care

peace absence of war
piece part of a whole; musical arrangement

peak point, pinnacle, maximum
peek to peer through or look furtively
pique fit of resentment, feeling of wounded vanity

pedal the foot lever of a bicycle or car
petal a flower segment
peddle to sell

personal intimate; owned by a person
personnel employees

plain simple, unadorned
plane to shave wood; aircraft (noun)

precede to come before
proceed to continue

presence attendance; being at hand
presents gifts

principal foremost (adj.); administrator of a school (noun)
principle moral conviction, basic truth

quiet silent, calm
quite very

rain water drops falling; to fall like rain
reign to rule
rein strap to control an animal (noun); to guide or control (verb)

raise to lift up
raze to tear down

rational having reason or understanding
rationale principles of opinion, beliefs

respectfully with respect
respectively in that order

reverend title given to clergy; deserving respect
reverent worshipful

right correct; opposite of left
rite ritual or ceremony
write to put words on paper

road path
rode past tense of "to ride"

scene place of an action; segment of a play
seen viewed; past participle of "to see"

sense perception, understanding
since measurement of past time; because

sight scene, view, picture
site place, location
cite to document or quote (verb)

stationary standing still
stationery writing paper

straight unbending
strait narrow or confining; a waterway

taught past tense of "to teach"
taut tight

than besides; comparison
then at that time; next

their possessive form of "they"
there in that place
they're contraction for "they are"

through finished; into and out of
threw past tense of "to throw"

thorough complete

to toward
too also; very (used to show emphasis)
two number following one

track course, road
tract pamphlet; plot of ground
waist midsection of the body
waste discarded material; to squander

waive forgo, renounce
wave flutter, move back and forth

weak not strong
week seven days

weather climatic condition
whether if
wether a neutered male sheep

where in which place
were past tense of "to be"

which one of a group
witch female sorcerer

whose possessive for "of who"
who's contraction for "who is"

your possessive for "of you"
you're contraction for "you are"
yore time long past