NOTE: The letters 'X' and 'Q' are not represented above - Since this key made by translating in-game text, letters which haven't been used can't be known. the two extra symbols, '#' and '@', are seen in-game but have no apparent meaning.
The Grineer speak and write in English and use the standard English alphabet, though they use a unique set of letters based on rectangles with barcode-style horizontal 'cuts' made along their left edges to various depths. A dot present under each letter's bottom-right corner helps to determine correct orientation and makes it easy to tell if text has been flipped or rotated.
Note that in many cases, it appears that the developers did not intend for this text to actually be translated and read by players. Therefore, many cases of text longer than a few words (such as the readouts on monitors) tend to be random letters strung together and occasionally flipped or rotated. Since letters only have marks on their left side, it is easy to tell when this has been done.
The simplest example is the text on the image to the right, which just says "GRINEER".
The words "FLAK 1.8" appears on both sides of the Drakgoon
The words "NOT TOUC" are written on both sides of Gorgon.
The word "GASER" is written all over Regulator.
The word "VIPER" appears on the side of the Viper handgun.
The word "CUTFACE" is written on the saw of the Miter.
The words on the Gremlin's magazine are "BULLETS FOR YOUR FACE".
The words on the Ogris appear to be "BIG HURT F#43#", with the '#' spaces totally obscured by strapping.
The word "ARMOR" also appears on the top of all Alloy Plates.
The word "UBER" appears on the Commander's helmet.
The word "KILL" appears on a small canister beneath the Torid.
The word "OBEY" is written on Acrid near the barrel.
"DEATH TO REST"
"DISOBEDIENCE LEADS TO DEATH"
"OBEY ALL SIGNS"
"WANT TO KNOW MORE?"
"BE GOOD OR BE GONE"
In the next two phrases, the 'K' appears to be a typo, since a distinct letter for 'C' also exists.
"SUPREMAKY IS DUTY"
"IF OUR ENEMIES DESERVED PEAKE, THEY WOULD HAVE DEFEATED US"
"VICTORY IS PROOF OF DESTINY"
"OUR STRENGTH IS OUR JUSTIFICATION"
"GRINEER DEFENSE ASSET GROUP AUGUST" ~ This appears on doors in the Grineer Galleon.
"ATTACK. CONKWUER. RULE." ~ Further proof of the lack of a 'Q' in the alphabet.
And the largest coherent text sample in the game so far:
AUTHORIZED PERSONNEL ONLY
THIS AREA CONTAINS HIGHLY SENSITIVE MATERIALS. ONLY GRINEER WITH PROPER ACCESS CREDENTIALS MAY ENTER THIS AREA. ALL OTHERS WILL BE TERMINATED."
A video released on July 3rd 2013 for a weekend event featured more Grineer text, including numbers for the language. A flash before the timer countdown contained the message:
"COMMANDERS, GLORIOUS NEWS, OUR NEW SURVEILLANCE DRONES ARE BEING DEPLOYED AS WE SPEAK
CENTRAL CONTROL WILL NOW BE ABLE TO MONITOR THE LOCATION OF EVERY TENNO
OPERATIVE IN THE SYSTEM. ANY ATTEMPTS TO TAMPER WITH THE DRONES WILL BE
THWARTED BY THEIR SOPHISITCATED DEFENSE SYSTEMS.
"OUR GRIP IS TIGHTENING.
SOON OUR DOMINANCE WILL BE UNCHALLENGED.
THE TWIN KWUEENS" (Queens, lack of Q showing up again)
The timer displayed in the background begins at 48:00:00, and begins counting down, ending at 47:59:51 when the view changes. As a result, we get the following symbols for numbers:
It can be seen that the numbers have indentations on the right sides of the blocks, unlike the letters which have indentations on the left sides. The indentations on the numbers progressively rise as the numbers increase. Even numbers have shallower indentations, while odd numbers have deeper ones.