adverbial N1 rare writtenliterary
ややもすれば — tend to ~
ややもすれば
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See ややもすれば in real sentences
Jengo shows ややもすれば the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Advanced Japanese Grammar. Editorial confidence: medium.