Cannot Convey Sarcasm

The inversion of Sarcasm Blind. Due to some characters' demeanor, it is hard for others to distinguish if they are being sarcastic. In this case it isn't that someone doesn't understand the concept of sarcasm -- it's that someone doesn't understand how to properly use it, despite knowing exactly what sarcasm is. Often they have to alert others that they are in Sarcasm Mode. May overlap with Insult Backfire and is closely related to Sarcasm Failure.

Advertising

 * Inversion: There was an old commercial for Starburst where a man asked a woman if she wanted a Starburst and she sarcastically replied something like "Yeah, sure I would." He asked her why she had to be so flippant and she sarcastically told him that she has a speech disorder which makes everything she says sounds sarcastic. He got annoyed and walked away, after which she maintained the sarcastic tone and lamented to herself how this speech disorder sucks.
 * Also a sketch from The Kids in The Hall where Dave Foley's character has the same speech disorder.

Comedy

 * Comedian Arj Barker had a joke suggesting we all use the made-up font Sarcastica when typing sarcastic comments.

Live-Action TV
"Oz: I can see why you'd be upset. Oh, that was my sarcastic voice.
 * Every so often, Sheldon from the The Big Bang Theory says something sarcastic but does it without much inflection. In one episode, Penny wants Sheldon to apologize to Leonard. When Sheldon refuses, Penny invokes this trope by telling Sheldon to apologize sarcastically. Sheldon agrees, and Leonard never realizes Sheldon is trying to be sarcastic.
 * Buffy the Vampire Slayer
 * Anya Jenkins, maybe. She is very inept handling human relationships and behaviour, so it is hard to tell for the Scoobies whether she is being sarcastic, just unknowing -- or plain insulting.
 * Oz, the extremely-Deadpan Snarker.

Xander: You know, it sounds a lot like your regular voice.

Oz: I've been told that."


 * Abed from Community (possibly) subverts this twice: Once where he goes out of his way to use sarcastic inflection when being sincere about the importance of inflection, and again where he lets the group know he's about to begin a sarcastic diatribe before doing so, and closes with "Sarcasm over".
 * Every so often Brennan and (at one point anyway) Zack from Bones (on the off chance that they'd actually use sarcasm).
 * Robin and her date have a misuderstanding in How I Met Your Mother in which he turns up in a Halloween costume while she doesn't, as her sarcasm didn't come across in their online conversations.
 * The Saturday Night Live sketch "Sarcasm 101 with Matthew Perry." They know what sarcasm is but they don't all quite get how to do it.
 * One sketch on So Random features "Possibly Sarcastic Skip", who was born with a disease that makes him soundsarcastic all the time. The sketch is spent trying to determine when he is and isn't being sincere.
 * Inverted in a Kids in The Hall sketch in which Dave Foley’s character inadvertently insults people due to his speech impediment which causes it to sound as though he’s perpetually being sarcastic.

New Media

 * The Internet comes standard with sarcasm filters built into HTML protocol, rendering it highly possible that offhand flippant comment you thought was the height of clever Lampshade Hanging insulted everyone who read it. Detecting sarcasm in text requires the reader to rely on wording and context alone, and a conversation between strangers provides a lot less context than one between friends. It might be related to the rampant overuse of italics to make something seem more outstanding or ALL CAPS SPEAK TO SUGGEST YELLING.
 * Sarcasm is nearly impossible to convey in text in general. The Internet is more noticeable in that sarcasm is more abundant, but when it appears in text, it can be hard to tell how genuine they're being.

Video Games

 * Maybe G La DOS from Portal. Her being a robot doesn't help. She might not have the intonation, but given that most of her sarcasm is the variety you would expect from a bratty six-year-old it isn't exactly difficult to make out. At least in the sequel she is promoted to teenager-level bitchiness.
 * Bowser's reaction to Mario and friends forgetting to invite him in Mario Party 7.
 * Sten from Dragon Age Origins. He's extremely stoic and does not seem to make jokes. However you can, at one point, tell him you recognize his jokes and you think he's funny, and he'll become much friendlier towards you as a result.
 * EDI from Mass Effect 2. She slowly becomes increasingly capable at humor, although her capability to convey sarcasm through tone of voice takes a bit more work. That, or she's just absolutely fine being a Deadpan Snarker.

Web Comics

 * Discussed in this strip of Dinosaur Comics, in which T-Rex worries that people can't tell when he's being sarcastic. (And then repeats that worry in a sarcastic tone.)

Web Original

 * Dr. Clef from SCP Foundation makes it impossible to tell whether he's lying or not, or whether he's even serious or not.

Western Animation
"Homer: There's still the little matter of the whereabouts of your wife.
 * The Simpsons
 * Inverted in the episode "Bart of Darkness":

Maude Flanders: Uh, I'm right here.

Homer: Oh, I see! Then I guess everything's wrapped up in a neat little package!

(after a pause)

Homer: Really, I mean that. Sorry if it SOUNDED sarcastic."

"Homer: And maybe I'm talking like this because I can't stop! Help me, Lisa! I have serious mental problems!"
 * Played with in "Bart Has Two Mommies", after telling Marge that Bart was kidnapped by a monkey:

"Teen 1: Here comes that cannon ball guy. He's cool.
 * In the episode "Homerpalooza" two unnamed teens/young adults engage in a form of this:

Teen 2: Are you being sarcastic, dude?

Teen 1: I don't even know anymore."