When Leonard learns Sheldon is the president of the tenants association, he decides to run against him. Also, Bernadette encourages Howard and Raj to find the owner of a drone…

Bill Gates visits Penny’s work, and the gang schemes to meet him. Hilarity ensues. Meanwhile, Sheldon is convinced that he’s a target of an April’s Fools prank.

Leonard jumps through hoops to help secure the perfect wedding venue for Sheldon and Amy. Also, Bernadette and Howard have a hard time deciding who should stay at home with…

When Bernadette won’t go into labor, the gang tries different tactics to get things started. Also, Howard confronts Bernadette after Amy accidentally reveals she’s already chosen their son’s name.

Leonard’s book raises questions, and Amy guest stars on the new Professor Proton show.

Raj finds himself in the middle of domestic drama when he learns the woman he’s dating, has a very upset husband. Also, when Sheldon rents his old room back for…

When Sheldon kicks Amy out to work solo, she and Leonard bond during a series of science experiments. Also, Bert the geologist replaces Wolowitz in the band Footprints on the…

Sheldon and Amy try to pick their Best-Man and Maid of Honor by experimenting on the gang.

Raj and Howard’s feud continues as the gang plan Halley’s first birthday party. Sheldon’s surprise for Amy’s birthday goes awry when they get food poisoning. Also, Leonard gets a Christmas…

Sheldon and Amy try to eliminate stress from wedding planning by applying math to the process. Also, Raj “breaks up” with Howard after realizing his best friend is actually hurting…

Sheldon tries to teach the guys a lesson after they cut him out of a potentially valuable Bitcoin investment. Also, a seven-year-old video reveals a secret about Leonard and Penny’s…

Leonard and Howard are furious after they learn Sheldon went to work with the military behind their backs. Also, while Bernadette is on bed rest, she asks Raj to do…

Sheldon and Bert collaborate on a research project, despite Sheldon’s embarrassment. Also, Penny and Bernadette coach Raj on how to navigate his relationship with Ruchi.

Sheldon goes head-to-head with Wil Wheaton for the role of the new Professor Proton. Also, Penny steps in to take care of Halley when Bernadette and Howard both wind up…

Sheldon and Raj confide in Bernadette when they can’t handle Amy and Howard working together on a science project. Also, Penny and Leonard learn new tactics for how to deal…

As Howard worries about fatherhood, he and Sheldon bond when they jointly assemble a model rocket. Meanwhile, Penny bonds with Leonard’s mother, Beverly, much to his concern.

Sheldon and Amy struggle with picking a wedding date, which stresses out Sheldon and causes him talking in his sleep. Meanwhile, Raj and Stuart fight over the attention of one…

Leonard angers the university – and the entire physics community – after he gives an embarrassing interview. Also, Amy and Bernadette bond over having to hide their success from Sheldon…

In the eleventh season opener, Amy gives Sheldon an answer to his proposal while Howard and Bernadette struggle with some unexpected news.

The gang is concerned when Sheldon’s former admirer, Dr. Ramona Nowitzki, resurfaces while Amy is away at Princeton.

After Leonard, Sheldon and Wolowitz celebrate the completion of the top secret air force project, they are met with an unpleasant surprise. Also, Amy is offered a summer position as…

Leonard isn’t thrilled when Penny considers taking a new job offered by her ex-boyfriend, Zack.

Howard and Bernadette have a hard time leaving Halley in day care when Bernadette returns to work. Also, Bert introduces the gang to his new girlfriend, Rebecca.

Sheldon pushes himself to the limit when he collaborates on projects with Leonard and Wolowitz as well as Amy on the same day. Also, Bernadette is nearing the end of…

Leonard, Penny and Raj adjust to their new living arrangement, and Sheldon takes an interest in Amy’s work.

With Koothrappali cut off from his father’s fortune, he appoints Sheldon to help him get out of debt. Also, Penny considers joining Leonard at Comic-Con.

When Raj moves out of his apartment, Leonard and Penny offer him Sheldon’s old room.

Sheldon and Amy have their first fight since moving in together, and Koothrappali is shocked at the realities of financial independence when he stops receiving support from his father.

Leonard and Wolowitz try to distract Sheldon when he slows the progress of their guidance system. Also, Penny and Amy take Bernadette out for the night, leaving Raj and Stuart…

Sheldon beta-tests an MIT invention after hearing it can help him read people’s emotions. Also, Leonard can’t hide his feelings when Penny announces her brother is coming to town, and…

When Penny feels that Leonard is taking her for granted, she decides to go on a spa weekend with Amy. Also, Wolowitz and Koothrappali try to fix a squeaky floorboard…

Sheldon and Amy visit Leonard and Penny for the first time since the holidays and share details about their terrible trip to Texas.

Howard and Bernadette welcome their new baby and Sheldon and Amy celebrate Amy’s birthday.

Sheldon and Leonard try to divvy up their shared belongings, but can’t agree on anything. Also, Koothrappali and Stuart fight to be the most helpful during Bernadette’s final weeks of…

When Bert, a Caltech geologist, wins the MacArthur Genius fellowship, Sheldon is overcome with jealousy. Also, Wolowitz finds an old remote control Stephen Hawking action figure he invented.

In order to continue living with Sheldon, Amy lies to him about repairs being made to her apartment and they host an “on location” episode of “Fun With Flags” in…

After a successful experiment combining their genes, Sheldon will stop at nothing to convince Amy they should procreate. Also, Koothrappali is embarrassed to tell the gang what the new woman…

Penny is surprised to learn she has fans of her performance in “Serial Ape-ist” when she attends Van Nuys Comic Con with Leonard. Also, Amy hosts a Sheldon-style brunch at…

Leonard and Penny must separate a quarreling Sheldon and Amy when their cohabitation does not go as planned, and Sheldon threatens to break off their relationship when Amy refuses to…

When Amy’s apartment floods, she proposes a “cohabitation experiment” with Sheldon. Also, Howard and Bernadette are upset when Koothrappali learns the gender of the baby before they do.