By Hannah Barnes
BBC News, Jerusalem
Jerusalem's Ben Yehuda Street is named after modern Hebrew's father
Modern Hebrew, which can now be heard everywhere on the streets of Israel, has continued to evolve since it was reintroduced as a living language.
At the top of a steep winding driveway, in a hidden corner of the Hebrew University, stands the Academy of the Hebrew Language.
Despite its grand title, it is a small, modest building, camouflaged by a circle of trees. It is impossible to find if you do not know where you are going - expensive, too, when the taxi meter is running.
The academy sets the standards for the use of modern Hebrew and adds new words to its vocabulary.
Inside its sand-coloured brick walls, there are books everywhere, piled high from floor to ceiling.
There are also pictures of Eliezer Ben Yehuda, the man many credit with reviving the Hebrew language more than 100 years ago.
For nearly 2,000 years, people did not speak Hebrew - at least not as a daily language.
Jews would pray in Hebrew in synagogues and read Hebrew in religious texts, but there were not any native Hebrew speakers.
The academy helps decide which words should be added to modern Hebrew
The first of them was Ben Yehuda's son, Itamar Ben Avi.
You would not envy him.
He had a thoroughly miserable childhood - home-schooled, locked up by his parents, and not allowed to play outside with other children so that he would not be exposed to any other languages.
For a long time people thought he would be mute. It was not until he was three-and-a-half that Itamar spoke his first Hebrew word.
Part of the difficulty in bringing an old language back to life was that, well, life had changed.
The words that existed in the Bible often described rather grand ideas like love, war, and peace.
But that was no help when trying to get shopping done - there were no words back then for ice cream or jelly or underwear.
So, Ben Yehuda and his friends simply made them up, using old Hebrew roots to hint at the new words' meaning.
And that process is still happening today.
In her small office inside the academy, I meet Keren Dubnov.
Originally from Russia, Keren is Hebrew's greatest enthusiast.
I fell in love with it
Keren Dubnov, Hebrew Academy
"I fell in love with it," she tells me, smiling.
She taught herself the language, and describes her current job as her "wildest fantasy". She answers the Hebrew hotline.
That probably conjures up images of a phone that flashes red when someone needs help urgently - "Please, I'm stuck in the supermarket - and I can't remember the name for cauliflower!" (It is "kruvit" just in case you were wondering.)
But sadly it is not like that. The service provided by the academy is very 21st Century - the hotline now operates through a web interface.
People can ask any question they like, but they can also suggest new words.
Ideas arrive every week, and some are more successful than others.
"We take all the letters seriously," Keren says. "Not all the proposals are serious though."
She tells me about the word "mets-hev-hev"
except it is not really a word, yet.
It has been proposed by a proud mother, whose daughter coined the word to describe a broken traffic light, one that is stuck on amber, and flashing.
In this case the young girl took the word for yellow, "tsahov", and the word for blinking, "me-hev-hev", and put them together to create something new.
"It's perfect slang," Keren beams. "I liked it very much but I couldn't keep it."
"Why not?" I ask. As if stating the obvious, she smiles and says: "Well it's not really needed!"
The modern Hebrew language is growing all the time.
Around 20 new words are officially added each year, but if you count technical vocabulary and jargon too, it can run into the hundreds.
Approving them can be a lengthy process. A committee has to consider them, and it can take several years to reach a decision.
And even after all that - there is no guarantee that the public will accept the words.
Language is a sensitive issue in Israel. It is even discussed in the Knesset.
In 2005, Israel's then prime minister Ariel Sharon chastised Israelis for using the Arab-English hybrid expression "yala bay" to say farewell to each other (you hear it everywhere in Israel).
Ben Yehuda kept his son at home while training him to be a native speaker
Instead, Sharon argued, they should be using what he referred to as "the most beautiful word", shalom.
There are so many foreign words in Israel today that the academy faces an uphill battle.
Why even bother to memorise a new Hebrew term when you can already get by perfectly well with the American slang of MTV presenters?
Hebrew purists might well be horrified by Ruth - a lean 17-year-old with piercings in her nose, ears and eyebrow, who I meet, appropriately, on Jerusalem's Ben Yehuda Street.
I am there to test a claim made by an academic that Israelis cannot understand the Hebrew of the Bible because of the influence other languages have had on its modern successor.
I am asking people to read and then translate a couple of Biblical verses.
Ruth's shorter, but equally confident friend immediately turns herself into a human beat box, producing a beat by making little rhythmic grunts, while Ruth raps the words.
Isaiah like you have never heard it before.
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