Meaning of -ATORY in English

-ATORY

-atory The British English and American English pronunciations of this suffix differ. In British English the vowel of the penultimate syllable is always weak: the suffix is either BrE AmE ət‿ ə r i or eɪt ə r i and, if the latter, may be stressed. Different speakers often pronounce differently. Thus ar ˈ ticulatory may have -jʊl ət‿ ə r i or -ju leɪt ə r i , or alternatively may be stressed ar ˌ ticu ˈ latory ◂ . In American English the suffix always has a strong vowel, ə tɔːr i ə toʊr i , stress remaining as for the corresponding verb in -ate: ar ˈ ticulatory, ˈ mandatory.

Longman Pronunciation English Dictionary.      Английский словарь произношений Longman.