Stress or accent

Look at these examples: introduction and eradicate

in tro 'duc tion
This word has four syllables: in - tro - duc- tion
-tion is the ultimate syllable
-duc is the penultimate syllable
-tro is the antepenultimate syllable
in is the first syllable.

The stress or accent is on the penultimate syllable.

e 'ra di cate

This word has four syllables: e - ra - di - cate
-cate is the ultimate syllable
-di is the penultimate syllable
-ra is the antepenultimate syllable
e is the first syllable
The stress or accent is on the antepenultimate syllable.

The stress or accent in the case of intro'duction is on the penultimate syllable and it is indicated by the mark ' placed on top and before the syllable that is stressed or accented. In the case of e'radicate the stress is on the antepenultimate syllable.

Some general rules for word stress:
All word endings like -tion, -cion and -ssion have the stress on the penultimate syllable.

• calcu'lation
• co'ercion
• communi'cation
• sus'picion
• prepa'ration
• pos'session
• edu'cation
• com'passion
• intro'duction
• re'jection

Words with three and more syllables ending in -ity have the stress on the antepenultimate syllable.

• ac'tivity
• elec'tricity
• crea'tivity
• produc'tivity
• elas'ticity
• rela'tivity

Words ending in -graphy have the stress on the antepenultimate syllable.

• bi'ography
• pho'tography
• ge'ography
• radi'ography

Words ending in -ical have the stress on the antepenultimate syllable.

• eco'nomical
• geo'graphical
• 'logical
• mathe'matical
• po'litical
• theo'retical

When -ly is added to words ending in -ical there is no change in the stress pattern.

• eco'nomical
• eco'nomically
• po'litical
• po'litically

Words ending in -cian have the stress on the penultimate syllable.

• acade'mician
• mathema'tician
• elec'trician
• ma'gician
• poli'tician
• statis'tician

Verbs with three syllables and more ending in -ate have the stress on the antepenultimate syllable.

• an'ticipate
• 'calculate
• con'gratulate
• 'educate
• e'radicate
• par'ticipate

Almost all words ending in -ic have the stress on the penultimate syllable.

• e'lastic
• elec'tronic
• fan'tastic
• philo'sophic
• syl'labic

Words ending in -logy have the stress on the antepenultimate syllable.

• bi'ology
• ge'ology
• psy'chology
• zo'ology

Functional Stress:
When the word is used as a noun or an adjective, the stress falls on the first syllable. When the same word is used as a verb, the stress falls on the second syllable. This is known as ‘functional stress’.

• 'present (noun).
• pre'sent (verb).

Stress Shift:
Some derivational suffixes affect the stress pattern of the main word.

• 'engine engi'neer
• 'magic ma'gician
• mathe'matics mathema'tician
• 'music mu'sician
• 'politics poli'tician
• 'active ac'tivity
• 'colony co'lonial
• 'science scien'tific

When -ly is added to those words ending in -ic and/or -ical, there is no change in word stress.

• e'lectric
• e'lectrical
• e'lectrically
• elec'tronic
• elec'tronical
• elec'tronically
• mathe'matics
• mathe'matical
• mathe'matically
• po'etic
• po'etical
• po'etically