“In words of two syllables ending in -er, the vowel e has the sound of e in her, slightly softened by lack of accent: toil&etilde;r, moth&etilde;r, work&etilde;r.”
Copy each word with syllable division hyphens and place the tilde (~) over unaccented &etilde;r:
Break down the 4 agentive nouns into their base action verb and the suffix -er:
Identify the 3 words where o has the short sound of u (/ʌ/) before voiced th: