Final answer:
The suffixes -ac, -al, and -ic all mean 'pertaining to', modifying the meanings of the words to which they are added.
Step-by-step explanation:
The suffixes -ac, -al, and -ic all mean 'pertaining to'. These suffixes are added to the ends of words to modify their meaning. For example, the suffix -ic in the word 'scientific' indicates that the word pertains to science. Suffixes such as -ac and -al function similarly, as seen in words like 'cardiac' (pertaining to the heart) and 'musical' (pertaining to music).
For example, 'cardiac' means 'pertaining to the heart,' 'personal' means 'pertaining to a particular person,' and 'heroic' means 'pertaining to a hero.'