To understand why R2-D2 does not speak Basic, we must appreciate that his primary function doesn't necessitate it. Instead, he communicates through beeps and boops, efficient for his role as a starship repair and navigational unit.
One aspect of R2-D2 that always mystified me was that he couldn't talk. C-3PO, his robot companion, could speak 6-million languages including excellent English with a hint of a British accent and all R2-D2 could muster were beeps and whistles.
The decision to take R2-D2's voice out of the equation was a genius call that helped make the character more memorable than through voiced dialogue. The beeps and whistles managed to convey emotions uniquely and endearingly. For example, when Artoo is annoyed, his beeps become louder and more frantic.
However, most droids, including R2-D2 and BB-8, "speak" a droid language through sequences of beeps and whistles. It is known as "Binary," and several humans in the Star Wars universe can understand it. Here are the handful of the humans who can and an explanation for why they're able to do so.
secondly, in Legends, R2 was given programming that actually restricted him. from sharing any information with Luke or Leia. about their parents or relation to one another. this was all part of the plan. to conceal this information from the twins.
Why Doesn't Obi-Wan Remember R2-D2 in A New Hope? - Star Wars Explained
Why does Vader not recognize R2-D2?
Darth Vader acts like he doesn't even know C-3PO or R2D2. They were with him since he was a child. He did everything he could to forget his past. Also, his plating had been replaced many times, and protocol droids all look very similar.
R2-D2 was present when Padmé gave birth to Leia and Luke, so he knew Luke was Anakin's son – but what he didn't know was that Anakin became Darth Vader. In addition to that, Anakin's fall was surely a painful event in R2-D2's life, one that he definitely wouldn't like to remember or even talk about.
R2-D2 (/ˌɑːr. tuːˈdiːtuː/) or Artoo-Detoo is a fictional robot character in the Star Wars franchise created by George Lucas. He has appeared in ten of the eleven theatrical Star Wars films to date, including every movie in the original trilogy, prequel trilogy, and sequel trilogy.
This took him on a wild journey, from recording scuba gear to capture Darth Vader's breathing, to capturing the hum from a projection booth at a cinema to create the iconic lightsaber sound.
All droids speak and understand Binary, given it's their first language. But only a few of the human characters in Star Wars can understand droids; Luke Skywalker wasn't the only one.
It may just sound like beeps and boops to us, but the droid-speak heard in Star Wars actually has roots in human conversation. Or at least BB-8's does.
A reliable and versatile astromech droid, R2-D2 has served Padmé Amidala, Anakin Skywalker, and Luke Skywalker in turn, showing great bravery in rescuing his masters and their friends from many perils.
Later, BB-8 says something to R2 that starts to stir him awake. “BB-8 comes up and says something to him, which is basically, 'I've got this piece of a map, do you happen to have the rest? '” Abrams said.
To understand why R2-D2 does not speak Basic, we must appreciate that his primary function doesn't necessitate it. Instead, he communicates through beeps and boops, efficient for his role as a starship repair and navigational unit.
A smart, spunky droid who would serve a multitude of masters over his lifetime, R2-D2 was never given a full memory wipe nor did he ever receive new programming, with these factors resulting in an adventurous and independent attitude.
C-3PO was created by the famous droid builder Anakin Skywalker, who later became Darth Vader. C-3PO was designed to be a protocol droid, meaning that his primary function is to communicate with other beings and to translate between different languages.
As a test, Yoda deliberately acted looney and tried to get on Luke's nerves, rummaging through Luke's belongings and attacking R2-D2 with his walking stick.
However, the same could not be said for R2-D2, who never had his memories erased. While there isn't a canonical reason for this decision, the likely explanation may have been that Threepio was more likely to say something he shouldn't have.
Darth Vader's true identity as Anakin Skywalker was a highly guarded secret, known only to a select few individuals including Palpatine, Obi-Wan Kenobi, Luke, Han, Leia, R2-D2, C-3PO, Master Yoda, Bail Organa, Ahsoka Tano, Darth Maul, Grand Moff Tarkin, Grand Admiral Thrawn, Jocasta Nu, Ferren Barr, Verla, Reva, ...
in the Dark Horse comic series star Wars Tales, which is now part of legends, it's revealed that Darth Vader did recognize C. 3PO on Cloud City. when 3PO was shot by Stormtroopers, his parts were brought before Vader. because the Imperials thought he could hold valuable.
The sequence calls back to a similar scene in Revenge of the Sith, when Bail Organa orders Threepio's memory be erased to prevent him from sharing information about Anakin Skywalker's fall to the dark side.
