Here's a breakdown:
di-
* Typically indicates "two" or "double" (e.g., dilemma, digital, dichromat).
* Can also be used to convey "separation" or "division" (e.g., divide, digress, distinct).
dif-
* Used to create opposites or contrasts (e.g., different, difficult, diffuse).
* Often used in words with the meaning of "not" or "lacking" (e.g., diffuse, difficult).
dis-
* Used to indicate "not" or "the opposite of" (e.g., disagree, dishonest, disappear).
* Can also convey "removal" or "separation" (e.g., disconnect, disassemble, dislodge).
Examples:
* Digression (to stray from the main topic).
* Difficult (hard to do).
* Disagree (to have a different opinion).
It's important to remember that these are just general guidelines. The specific meaning of each prefix can vary depending on the context and the word it is attached to.