To afford something means to have enough money to pay for it without causing financial hardship. If you can afford a new bicycle, you have the money to buy it and still have enough left for other things you need. If you can't afford it, buying it would leave you short on money for important expenses.

The word extends beyond money to other resources like time and energy. A student who stays up late every night might say, “I can't afford to lose any more sleep” because they're already exhausted. A team working on a tight deadline can't afford to make mistakes because there's no time to fix them.

Afford also means to provide or give something, though this usage sounds more formal. A hilltop affords a great view of the valley below. A good education affords opportunities for success.

When you're deciding whether you can afford something, you're really asking whether spending that money, time, or energy is worth what you'd have to give up. Your parents might say they can't afford an expensive vacation, meaning the money would be better used for necessities or savings.