What do the prefixes in, ad, and ob represent?

The prefixes in, ad, and ob represent assimilated prefixes because they undergo changes in form when attached to certain base words. These prefixes blend with the initial sounds of the base words they precede, often resulting in a change of the prefix's form for easier pronunciation. For example, "ad" changes to "ac" before a labial consonant as in "accommodate," while "ob" might change to "oc" before a velar consonant, as in "occur." This phonetic adjustment aids in smoother articulation, demonstrating how these prefixes assimilate to fit with the following sounds in the base words. Recognizing this assimilative behavior helps in understanding the etymology and transformation of words in the English language.