In both Dave's and dad's. Dad belongs to Dave and group belongs to dad.
As a plural, for more than one dad; no, does not need an apostrophe. As a possessive, as in the item belonging to dad, then yes, it does need an apostrophe.
Yes. The race belongs to the mums and dads so a possessive is required. "Mums' and Dads' Race" would be correct.
Between the second d in dad and the s in dad. dad's mug.
Dads aggrandize their money.
Dads aggrandize their money.
The little girl plowed her dads garden.
Because the apostrophe follows the plural noun dads, the possessive form means that it applies to more than one dad. Note that a capitalized Dad (a specific person) must be singular.
The stubbles on my dads face were very scratchy.
My dads buggy is so small that he could drive it to the woods
When he got home from work, my dads hands were very greasy
my mom uses starch on my dads shirts so they are always crisp and clean for work.
your two dads is very proud of you for asking that and so am i