The cast of "Modern Family"

Sitcom fans rejoice: the format isn't dead yet. Bearing in mind that it's a genre that goes back 75 years (yes, way back to radio), it's a miracle that anyone is still able to bring something new and fresh to the table. Is it any great surprise that so many attempts at the half-hour comedies flop within the first season?

How refreshing then – particularly for those who spurn the reality shows that are currently devouring prime time – when a sitcom not only survives but thrives well beyond its first season. "Modern Family," which airs Wednesdays on ABC, has accomplished such a feat and is now in its fifth season.

The series became an instant favorite following its 2009 debut, for which 12.6 million viewers tuned in. Since then, the show has enjoyed immense popularity and has been among Wednesday night's top shows in the critical demographic of adults aged 18 to 49. It's received 57 Emmy nominations and taken home 18 of the awards, including Outstanding Comedy Series four times running – every season it's aired. It's also won other Emmys for Outstanding Supporting Actor for Ty Burell and Eric Stonestreet and Outstanding Supporting Actress for Julie Bowen, and in 2012, the series also took home the Golden Globe Award for Best Television Series – Musical or Comedy, among many more accolades.

"Modern Family" follows the members of three distinct family units, all connected as part of a larger blended family. Jay (Ed O'Neill, "Married With Children") is the patriarch of the brood and is married to his much younger second wife, a voluptuous Colombian firecracker named Gloria (Sofia Vergara, "The Knights of Prosperity"), who is mother to a wise-beyond-his-years son named Manny (Rico Rodriguez, "Babysitters Beware," 2009). Jay's grown daughter, Claire (Julie Bowen, "Boston Legal"), is a stay-at-home mother of three in a traditional family with her husband Phil (Ty Burrell, "Out of Practice"). Claire's brother, Mitchell (Jesse Tyler Ferguson, "The Class"), and his partner, Cameron (Eric Stonestreet, "CSI"), are loving fathers to Lily (Aubrey Anderson-Emmons), whom they adopted from Vietnam as a baby in the series opener.

Reception has remained generally positive for the series, which recently aired its 100th episode. Yet what goes up must come down, at least once in a while. Ratings for this year's hour-long season premiere, which aired Sept. 25, were down 25 per cent from last year's. With a decrease of nearly two million viewers and more than a point among adults in its demographic from the previous season, this year marked the show's least-watched season premiere so far.

After four solid seasons, of course, any series is in danger of running out of steam, and "Modern Family" can't venture too far from the structure it's followed to date. As the series is presented in a mockumentary style, the storylines must stay within the scope of the believable. The show's writers face the weekly challenge of depicting real-life scenarios while making ordinary events comedic. The humor comes from the characters' various eccentricities and the way they approach and deal with everyday situations.

Sofia Vergara stars in "Modern Family"

In fact, the concept came from creators Christopher Lloyd and Steven Levitan exchanging stories about their families and realizing that those stories could be the foundation of a show. The idea is to give an "honest and often hilarious look into the sometimes warm, sometimes twisted, embrace of the modern family."

Fortunately, families change, grow and gain new problems and experiences, and the aspect of an ensemble cast has helped keep things fresh for four seasons. With characters spanning a wide range of ages, backgrounds and experiences, an episode can go in any different number of directions.

So what have these natural progressions put on the table to keep "Modern Family" alive? Jay – already a grandfather four times over – and Gloria have a new baby to rear. Phil and Claire's oldest daughter, Haley (Sarah Hyland, "Cougars Inc.," 2011), is grown up and, after getting expelled from college, has to figure out what she wants to do with her life. Their youngest, Luke (Nolan Gould, "Friends With Benefits," 2011), and Manny have just entered the lion's den of high school, and with the kids getting older, Claire can now look into rejoining the workforce.

As for Cam and Mitchell, thanks to the U.S. Supreme Court's recent decision to allow same-sex marriage in California, the two can now officially tie the knot – and they will. Season 5 opened with a landmark episode in which the guys got engaged and, in keeping with the ensemble cast format, the whole family was enlisted to help with the proposal. This particular storyline will also provide ongoing material for this season, as writer Jeffrey Richman told "The Hollywood Reporter": "It sort of gathered momentum because it wouldn't just be a one-off story. It would give us episodes leading up to a wedding, and we're so hungry for stories."

Ratings slumps aside – and it should be noted that decreased audience numbers are by no means consistent – it sounds as though "Modern Family" has no shortage of new story potential coming our way. It may not be able to keep up the kind of freight train momentum with which it started, but that doesn't mean it will fail to keep audiences entertained from week to week. Tune in to see what else is in store for this modern family Wednesdays on ABC.