Brazilian Portuguese Grammar

Rules of accentuation

The use of accent marks

1. All proparoxytones must get an accute accent (open vowels) or a circumflex accent (closed vowels):

Portuguese	English
pântano	swamp
ônibus	bus
bêbado	drunkard
íngreme	steep
úmero	umerus

2. All paroxytones ending in -l, -on, -ons, -ps, -r and -x must get an accute accent (open vowels) or a circumflex accent (closed vowels):

	Portuguese	English
-l	projétil	projectile
-on	nêutron	neutron
-ons	prótons	protons
-ps	bíceps	biceps
-r	câncer	cancer
x	ônix	onix

3. All paroxytones ending in -ã, -ãs, -ão, -ãos, -i, -is, um, uns, and -us must get an accute accent (open vowels) or a circumflex accent (closed vowels):

	Portuguese	English
-ã	ímã	magnet
-ãs	ímãs	magnet
-ão	sótão	attic
-ãos	bênçãos	blessings
-i	táxi	taxi
-is	lápis	pencil
-um	álbum	album
-uns	fóruns	forums / courthouses
-us	Vênus	Venus

4. All paroxytones ending in an oral diphthong must get an accute accent (open vowels) or a circumflex accent (closed vowels):

Oral diphthongs	Portuguese	English
-ea(s)	área	area
-ei(s)	répteis	reptiles
-eo(s)	óleo	oil
-ia(s)	idéias	ideas
-ie(s)	cárie	caries
-io(s)	relógio	clock, watch
-oa(s)	Páscoa	Easter
-ua(s)	água	water
-ue(s)	bilíngües	bilingual
-uo(s)	árduo	arduous

5. All oxytones ending in -a, -as, -e, -es, -o, -os, -em and -ens must get an accute accent (open vowels) or a circumflex accent (closed vowels):

Oral diphthongs	Portuguese	English
-a	Paraná	a southern Brazilian state
-as	anãs	female dwarfs
-e	maré	tide
-es	vocês	you (guys)
-o	cipó	liana
-os	avós	grandparents
-em	também	too, also
-ens	reféns	hostages