How to Pronounce “efficacious”

American (US)

/ˌɛf.əˈkeɪ.ʃəs/

British (UK)

/ˌɛf.ɪˈkeɪ.ʃəs/

Australian (AU)

/ˌef.əˈkæɪ.ʃəs/

adjective — Effective; possessing efficacy.

Example: This medicine is efficacious.

Where the stress falls. “efficacious” has 4 syllables, and the transcription /ˌɛf.əˈkeɪ.ʃəs/ puts the primary stress mark (ˈ) before the third one — so the third syllable is the longest and loudest. The others are said quickly and lightly.

An unstressed vowel reduces to schwa. /ˌɛf.əˈkeɪ.ʃəs/ contains a schwa /ə/ — the short, neutral “uh” that English unstressed syllables collapse into. Saying /ə/ there, instead of the vowel the spelling suggests, is most of what makes the word sound native.

What does "efficacious" mean?

efficacious (adjective): Effective; possessing efficacy. For example — This medicine is efficacious.

How do you pronounce "efficacious" in American vs British English?

American English: /ˌɛf.əˈkeɪ.ʃəs/. British English: /ˌɛf.ɪˈkeɪ.ʃəs/. Play both on this page to hear the difference.

What is the IPA transcription of "efficacious"?

/ˌɛf.əˈkeɪ.ʃəs/ in American English, /ˌɛf.ɪˈkeɪ.ʃəs/ in British English, /ˌef.əˈkæɪ.ʃəs/ in Australian English.

Which syllable is stressed in "efficacious"?

“efficacious” has 4 syllables, and the transcription /ˌɛf.əˈkeɪ.ʃəs/ puts the primary stress mark (ˈ) before the third one — so the third syllable is the longest and loudest. The others are said quickly and lightly.