The episode begins with Phil Dunphy excitedly preparing for his son Luke's 13th birthday. Phil is determined to make it a memorable occasion, emphasizing the importance of this milestone as Luke transitions into his teenage years. He has planned a special surprise for Luke, which he believes will help him embrace the responsibilities of growing up.

Meanwhile, Claire Dunphy is preoccupied with her own concerns about Luke becoming a teenager. She worries about the changes that come with adolescence and is particularly anxious about Luke's potential to become more independent. Claire's protective instincts kick in as she tries to ensure that Luke remains grounded and responsible.

As the family gathers to celebrate Luke's birthday, Phil reveals his surprise: a brand-new car for Luke. The car is a used vehicle, but Phil presents it as a significant gift that symbolizes trust and maturity. Luke is initially thrilled, but Claire quickly expresses her disapproval, fearing that Luke is not ready for such a responsibility. This leads to a heated discussion between Phil and Claire about parenting styles and the right way to handle Luke's transition into adulthood.

In a parallel storyline, Gloria Pritchett is dealing with her own challenges as she tries to help her son, Manny, navigate his teenage years. Manny is feeling the pressure of growing up and is struggling with his identity. Gloria, wanting to support him, decides to take him out for a special day to bond and discuss his feelings. However, Manny is reluctant and feels embarrassed by his mother's attempts to connect with him.

Back at the Dunphy household, the tension escalates as Claire and Phil argue about the car gift. Claire believes that Luke should earn the privilege of driving, while Phil insists that giving him the car is a way to show trust. This disagreement highlights the differing approaches they have towards parenting, with Phil being more lenient and Claire being more cautious.

As the day progresses, Luke's excitement about the car begins to wane, and he starts to feel the weight of the expectations placed upon him. He confides in his sister, Alex, about his fears of not being ready for the responsibilities that come with being a teenager. Alex reassures him, but Luke remains uncertain about how to handle the changes in his life.

In a pivotal moment, Claire decides to take a step back and reflect on her parenting approach. She realizes that her overprotectiveness may be stifling Luke's growth. Meanwhile, Phil, recognizing the importance of compromise, suggests that they set some ground rules for Luke's driving. This decision marks a turning point in their parenting dynamic, as they begin to work together to support Luke's transition.

The episode culminates in a heartfelt moment where the family comes together to celebrate Luke's birthday. They acknowledge the challenges of growing up and the importance of trust and communication. Phil and Claire present Luke with a set of driving rules, emphasizing that while he has the freedom to drive, he also has responsibilities to uphold. Luke feels a sense of relief and gratitude, understanding that his parents are there to guide him through this new phase of life.

In the final scenes, Gloria and Manny return from their day out, having had a meaningful conversation about growing up. Manny expresses his appreciation for his mother's support, and they share a tender moment that reinforces their bond. The episode ends on a positive note, with the families reflecting on the joys and challenges of parenting and the journey of growing up.

In the ending of "And One to Grow On," the episode concludes with Phil and Claire realizing the importance of being present for their children as they grow up. Meanwhile, Cam and Mitch face the challenges of parenting and the need to adapt to their daughter's needs. The episode wraps up with a sense of unity among the families, highlighting the joys and struggles of parenthood.

As the episode draws to a close, we see Phil and Claire Dunphy reflecting on their parenting journey. They have just celebrated their son Luke's birthday, which has prompted them to think about how quickly their children are growing up. Phil, in his typical enthusiastic manner, expresses his desire to be more involved in Luke's life, realizing that he needs to cherish these moments before they slip away. Claire, while supportive, also acknowledges the challenges of parenting and the need to balance their roles as parents with their own lives.

In another part of the house, Cam and Mitch are dealing with their own parenting dilemmas. They have been trying to navigate the complexities of raising their daughter, Lily, who is growing more independent. The couple has a heartfelt conversation about their fears and hopes for Lily's future, emphasizing the importance of being attentive to her needs as she matures. They come to a mutual understanding that they must adapt their parenting styles to support her growth.

The episode culminates in a family gathering where all the characters come together, showcasing the bonds that tie them. Phil and Claire, along with Cam and Mitch, share a moment of laughter and reflection, reinforcing the idea that despite the challenges of parenting, the love and support of family is what truly matters. The final scenes depict the families enjoying each other's company, celebrating the milestones of their children, and embracing the chaos that comes with family life.

In summary, the ending of "And One to Grow On" emphasizes the importance of being present for one's children, the challenges of adapting to their growth, and the strength found in family unity. Each character leaves the episode with a renewed sense of purpose in their roles as parents, ready to face the future together.

In the episode "And One to Grow On" from Season 5 of Modern Family, there is no post-credit scene. The episode concludes without any additional content after the credits roll. The focus remains on the main storyline and character interactions throughout the episode, which centers around the themes of growth and maturity, particularly as the characters navigate their relationships and personal challenges.

In this episode, Alex celebrates her 18th birthday.

Claire feels a mix of pride and sadness about Alex turning 18, as it signifies her daughter growing up and moving towards adulthood.

Phil gives Alex a heartfelt gift, which is a scrapbook filled with memories from her childhood.

Jay tries to make Alex's birthday special by giving her a car, but he ends up feeling frustrated when she doesn't appreciate it as much as he hoped.

Alex feels overwhelmed by the various birthday celebrations planned by her family, as they each have their own ideas of how to celebrate her milestone.

In "And One to Grow On," the episode contains a few elements that may be considered objectionable or upsetting for children or sensitive viewers.

1. Discussion of Death: The episode touches on themes of mortality and the impact of losing a loved one, which may be heavy for younger audiences.

2. Emotional Conflict: There are scenes that depict emotional struggles and conflicts among family members, which could be intense for some viewers.

3. Mild Language: There are instances of mild language that may not be suitable for all children.

4. Parental Concerns: The episode includes discussions about parenting and the challenges that come with it, which may resonate differently with various audiences.

Overall, while the episode maintains a comedic tone typical of "Modern Family," these elements could be sensitive for some viewers.