You've adopted that adorable 8-week-old puppy named Milly, but you're unsure when she will really listen to you and learn. Developmentally, she's had the smarts since she was about 4 to 6 weeks of age, so she's ripe for learning. But this isn't just about Milly, it's how you effectively communicate so she listens to you every time.
Take Things Slow
As soon as she comes home, begin short, consistent training sessions. In addition to housebreaking and reinforcing her name, pick one easy task such as "sit." Give commands in a calm, quiet voice, but don't overdo training time; it will bore and distract her. End your sessions on a positive note so she looks forward to the next one.
Once she masters that first command, move to another easy one; you want her to succeed. Reward her efforts with verbal praise and a small treat, incentives that remind her it's worth listening and reacting positively. Once she's tuned in to your voice, is fully vaccinated, and is at least 3 to 4 months of age, Milly's ready for a formal puppy class.