What's the difference between a condition precedent and a covenant in a purchase agreement?

They serve different jobs in the same agreement. A condition precedent is a state of affairs that must exist before a party is obligated to close at all — if it isn't satisfied (and isn't waived by whoever it protects), that party generally has no obligation to complete the transaction, full stop. Typical examples include no material adverse change having occurred, required consents being obtained, or specific representations remaining true as of closing.

A covenant, by contrast, is a promise to do (or not do) something — usually to actively bring about a result, like using reasonable efforts to get a required consent, operating the business in the ordinary course between signing and closing, or not soliciting other buyers during an exclusivity period. Breaching a covenant doesn't automatically excuse the other party from closing the way an unsatisfied condition can; instead, it typically gives rise to a claim for damages, or in a serious enough case, may itself trigger a related closing condition (like "all covenants have been performed in all material respects").

In practice, the two work together — many covenants exist specifically to help satisfy a related condition — which is why a Treadstone business lawyer reviews them as a connected package, not in isolation.