Here are the rules that we use while stressing words in English:
Stress is placed on the root word. Suffixes and prefixes are not stressed.
Mis.use
Dis.like
Mis.trust
Mis.take
Un.condition.al
Mis, dis and un are not stressed because they are prefixes.
al too is not stressed because it is a suffix.
Regardless of whether the word is used as a noun or verb eg mis.use the first syllable
cannot be stressed because it's an affix(prefix/suffix)
NB:Throughout this long write up, the full stop indicates syllable boundary.
2.Stress falls on the syllable with a diphthong e.g prosecute
Pro. se. cute
Pro is stressed because it has a diphthong /ou/
3.Stress falls on the syllable with the long vowel sound
e.g in agreement, markbook
a. gree. ment
gree is stressed because it contains a long vowel sound double e=/i:/
Mark.book
Mark is stressed because it has a long vowel sound ar =/a:/
Book has a short vowel sound double o in book produces the short o
4.In words containing suffix -ic, stress falls on the penultimate, second last
syllable.
You count from your right, the last syllable being ic
Photo. graph. ic
Stress falls on graph.
Scen.ic
Stress falls on scen since it's second from last
Hor. rif. ic
Stress falls on rif since its the second last syllable
Scien. tif.ic
Stress falls on tif since it's the penultimate
5.In a word where you have a long syllable and a short syllable,or a mono
syllable,stress falls on the longer syllable
a. buse
a. larm
Con. dition
Stress falls on buse, larm and dition, the longer syllables.
Regardless whether the word is used as a noun or verb, the second, longer syllable is
stressed.
6.In words that have double consonants
ap.proach /a.pproach
a.ssist/as.sist
a.ccent/ac.cent
Me.ssage /mes.sage
You stress the longer syllable that remains after the boundary or that remains with
the double consonants ,which will be the second syllable.
NB: There are exceptions to this rule :
Col.league
Chal.lenge
The stress in the words above is on Col and chal though they are the shorter syllable and don't have the double consonants.
7.Stress falls on the first syllable if a word is used as a noun or adjective
Re.fuse
Up. set
Pro. duce
Sub. ject
Per. fect
Fre. quent
Thus re, up, pro, sub, per and fre are stressed.
There are exceptions eg ad. vice which though a verb, has the stress falling on the second syllable like its verb counterpart
ad. vise .
8.Stress falls on the second syllable if a word is used as a verb
im. port
re.ject
con. duct
con. tent
re. fuse
Per. fect
Fre. quent
Thus port, ject, duct, tent,fuse,fect and quent are stressed.
There are exceptions to this rule
man. age
re. gis. ter (used as a verb)
The two have stress on the first syllable.