Broken Step

One of the main running gags in the show is a broken step being tripped over

Modern Family uses a comedy technique known as Running Gags to provide comedic relief.

The Broken Step

The Dunphys' home has a broken step near the top of the staircase. It's tripped on frequently by people, mainly Phil and Claire. The former repaired it before Earthquake only for it to become broken again after the event.

Gloria's Accent

Gloria has a very thick accent that leads her words to come across wrong.

For example Gloria intended to order "Baby Cheeses" but her thick accent caused her to order "Baby Jesus" so she wound up with several nativity scene styled baby Jesuses.

Phil's Fixation with Gloria

Throughout the series Phil is shown with quite a fixation on Gloria, taking any opportunity to touch her or be around her. It is also a running gag that Phil mistakes what Gloria says with different, mainly sexual references, like when she says she "had two ever since I was 2 years old and very big", referring to earrings. Although he is still very much in love with his wife Claire, whose attractiveness he is reminded of when he finds out his high school nemesis was jealous of him for having dated her.

The Raccoon

In several of the episodes, the raccoon has made an appearance (or is mentioned). First, in "Run for Your Wife," when Claire says the she gets really gets up at 6, Phil says, "Really? I... thought that was a raccoon." This has been repeated in "Regrets Only", when Phil sprays Claire with a fire extinguisher, thinking that it was a raccoon climbing into their house. In "Up All Night," Cameron tries to give an excuse to rush to Lily when she cries, by saying that "raccoons need something to put between ... bread." (Since Mitchell is trying to ferberize the baby, he is preventing Cam from coddling her). In "Truth Be Told," Jay pretends that a raccoon climbed in and killed Manny's pet turtle. And in Treehouse Phil asks Luke, "You know what can't climb trees?" and Luke says "Raccoons?" Phil replies, "Worries. Raccoons can and will get up here, so don't leave any food, or they'll get territorial and attack." In "The Old Wagon," Phil says that the old wagon has been enjoyed by a family of raccoons for many years. In the fourth season premier "Bringing Up Baby", Dylan says that he's going to be living with a friend, which he reveals is actually a raccoon.

"Of course you are"

In several episodes, especially in the first season, Jay tells Manny "of course you are," or a slight variation of it. He tells it to him when he says he is doing his science extra credit ("Up All Night"), when he introduces his older date ("Fifteen Percent")

Clive Bixby

This is the character Phil plays when he and Claire go out for Valentines shennanigans.

Cam's Bicycle Shorts

Cameron owns a pair of tight shorts that he uses for physical exercise. In every appearance the blue tight shorts have a pixelation in front of it, implying that the shape of Cam's penis is visible through it. In Strangers on a Treadmill, Mitchell has Claire tell him that he should not use the shorts anymore, this sends Cam into the bedroom, crying. Though he is seen wearing it on later occasions.