Say It Clearly, Translate Better: Using Controlled English for Content Creation

One misunderstood sentence can lead to costly errors, safety risks, or unhappy customers. That’s one of the reasons why more and more organizations are adopting Controlled English: a streamlined, rules-based version of the English language that prioritizes precision, simplicity, and consistency. Clarity in communication is critical from launching a new product, to delivering online support. 

What Is Controlled English in Translation?

Definition: Controlled English is a simplified form of English governed by specific rules to reduce ambiguity and complexity. It avoids idioms, which can be complex to transfer to another language, favors consistent vocabulary, and uses standard sentence structures. Unlike everyday English, it’s designed with non-native speakers and machine translation systems in mind.

Using clear, consistent language isn’t just easier for readers. Controlled English affords significant time and cost savings both for developing source English content and for subsequently translating it into one or multiple languages. It’s essential for maximizing translation memory savings to increase content reuse, and consequently reduce duplicated translation efforts, while also eliminating costly retranslation fees caused by linguistic variation.

Understanding the concept, benefits, and best practices of Controlled English can reduce translation costs, improve turnaround times, and increase consistency and clarity.

Controlled English Examples

One of the best-known versions is ASD-STE100, originally developed for aerospace maintenance manuals. Now, Controlled English is widely used across industries like IT, manufacturing, legal compliance, and technical documentation to ensure clarity and consistency on a global scale.

Any information contained in a text written in Simplified Technical English should be:

• Precise: The concept must be expressed with the utmost accuracy.
• Complete: Containing all necessary data.
• Pertinent: Referring only to the subject matter at hand.
• Concise: Expressing a lot of information in a few words.
• Credible: It must be convincing.
• Eloquent: Expressing concepts clearly.
• Unambiguous: Expressing concepts unequivocally.

For example, we can find segments like these, which in fact mean the same thing, but are expressed in different words:

• “To assemble, repeat the steps for disassembly in reverse order.”
• “To assemble, follow the steps in the reverse order.”
• “The assembly process is carried out in the opposite order to disassembly.”
• “Set up is done by reversing the order of the steps.”
• “To assemble, repeat the steps for disassembly backwards.”
• “Assembly is carried out by performing the steps in reverse order.”

Such cases (actually taken from one client’s corpus of documents) involve unnecessary expenses for the client, as those sentences that might already be in the translation memory will have to be retranslated.

Why Controlled English Improves Translation

When preparing content for localization, what you write in the source language sets the tone for everything that follows. Controlled English turns your content into a strategic asset, delivering tangible benefits across cost, speed, and quality.

Improved Consistency

When sentences follow a consistent structure and standardized wording, Translation Memories (TMs) can automatically recognize and reuse them. This means translators don’t have to retranslate content that has already been approved — saving both time and money.

However, even small changes can break this connection.
For example:

• “Submit your request.”
• “Please submit your request below.

Although these sentences communicate the same idea, the second version is considered a new segment. The TM can’t match it so it must be retranslated from scratch.

By reducing unnecessary variations in phrasing, Controlled English ensures:

• More segments are reused
• Fewer sentences are billed as new translations
• Your course maintains consistent terminology and style across every update and every language

Reduced Ambiguity

Clear, precise language helps translators immediately grasp the intended meaning without having to guess or seek clarification. That reduces the risk of misinterpretation in the target language, and also saves time.

Fewer ambiguities mean fewer queries from translators. Rework is minimized, and translation memory tools (like Trados Studio or Phrase) become more effective and leads to significant cost savings.

Higher Quality Output

Let’s compare, as an example, a typical sentence to its Controlled English counterpart:

Natural English:
“Make sure the power is off before working on the unit.”

Controlled English:
“Disconnect power before servicing unit.”

The second version is not only 45% shorter and more direct, but also less open to interpretation. For a human translator, or a machine, it’s clearer and easier to localize into other languages accurately.

Translation Memories Save Money, Time, and Effort

When content is already clear and structured, translators can work more efficiently. Plus, less time is needed for review and quality assurance.

Ultimately, consistent writing upfront prevents unnecessary expenses later and makes your global content clearer and more user-friendly for every learner.

Real-World Use Cases

Controlled English isn’t theoretical, it’s already delivering real results in high-stakes environments:

• Aerospace: Boeing and Airbus use ASD-STE100 (Simplified Technical English) to produce aircraft maintenance manuals that meet global regulatory requirements. This standard ensures clarity for international technicians and improves translation accuracy.

• Software Developers: User interfaces, help text, and documentation are often written in Controlled English to ensure consistency across languages.

• Regulatory and Legal Fields: Companies writing for international compliance use Controlled English to avoid misunderstandings and align with legal standards.

• Manufacturing & Automotive: Caterpillar Inc. developed its own version called Caterpillar Technical English to streamline documentation for heavy machinery. Swedish truck manufacturer Scania uses ScaniaSwedish, a controlled version of Swedish for technical writing.

• Technology & Software: IBM created Easy English, a controlled language for software documentation. SMART Communications uses Controlled English for global telephony documentation, validated by tools like the MAXit Checker.

• Research & Academia: The German Institute for Computer Science Research developed CLAT (Controlled Language Authoring Technology) for technical documentation. Universities like UniNettuno offer certification courses in ASD-STE100, showing its academic and industrial relevance.

Control Natural Language Case Study: Perkins Engines Company Limited

In the early to mid 1980s, I was working at WCC – Worldwide Communications Corporation. WCC was the most successful developer and marketer of Computer Assisted Translation software (now referred to as Machine Translation (MT)) in terms of total systems sold and implemented.

One of our clients, UK-based Perkins Engines Company Limited, is primarily a diesel engine manufacturer for several markets including agricultural, construction, material handling, power generation, and industrial. It was established in Peterborough, England in 1932, and has been a subsidiary of Caterpillar Inc. since 1998.

The Challenge and The Goal

As with most organizations at the time, there would sometimes be a significant lag between the release of English technical manuals and their translated versions. Perkins Engines set an objective for itself to simultaneously release its diesel engine technical manuals in English, French, German, Italian, and Spanish. It was 1980, and Perkins approached WCC for assistance.

WCC realized that for Perkins Engines to achieve their objective, a Controlled English environment needed to be developed to facilitate translations into multiple languages.

Developing the Work

Working together, Perkins Engines’ Technical Publications Department and WCC developed their PACE (Perkins Approved Clear English) system in 1980. Developed following the Caterpillar model, PACE primarily utilized a single wordlist along with a set of general writing guidelines. It was created in order to simplify the English used in technical documents, making them easier to understand for non-native speakers, and to facilitate the translation process. Once the PACE system was ready, WCC built electronic dictionaries in the CAT systems around the PACE corpus for subsequent language translation.

This was a massive effort given the volume of technical terms and their target language equivalents that needed to be input into the WCC CAT systems. With countless trial and error generating rough translations in four languages, analyzing the output, and then going into each language dictionary to resolve the issues, this was definitely not a quick fix.

However, the project paid dividends in 1983 when Perkins was able, for the first time in the company’s history, to release technical manuals simultaneously in five languages. This was unheard of at the time, and prompted several companies to embark upon similar initiatives.

Not only was Perkins Engines able to achieve its primary objective of simultaneous release of multilingual documentation, but they realized significant cost savings to their translation budget due to the reduced volume of redundant, inconsistent, and many times vague terminology.

Tips, Tools, and Standards That Make Controlled Language Work

To implement Controlled English effectively, organizations use specialized tools and follow well-established standards:

Getting Started Tips:

• Standardize terminology early. Create a glossary of key terms and enforce usage across all teams.
• Write short, direct sentences using an active voice. Avoid unnecessary adjectives or complex phrasing.
• Stick to one concept per sentence. Prevents ambiguity and rework during translation.
• Avoid synonyms. Pick one approved term and use it consistently every time.
• Use common, easily translatable vocabulary. Reduce idioms, slang, and figurative language.
• Structure instructions clearly. Use numbered steps and consistent formatting.
• Review content before sending to translation. Catch inconsistencies that would reduce translation memory reuse.

Enterprise Tools:

• Acrolinx and HyperSTE help writers check content against Controlled English rules in real time.These tools can be integrated into content management systems for enterprise-scale implementation.

Standards:

• ASD-STE100 (Simplified Technical English) is the most widely used controlled language standard in aerospace and defense.
• Other industries adapt similar guidelines to fit their documentation needs.

Final Thoughts: The Untapped Advantage

Controlled English is a quiet game-changer. Its rules might seem restrictive at first, but the payoff is enormous: faster translations, lower costs, and more effective communication with a global audience. So why isn’t everyone using it yet? Mostly because old habits die hard. But in a world where clarity and strategy drives revenue operations, Controlled English may be the smartest writing strategy you haven’t adopted yet.

Interpro Can Help: Say it Clearly. Translate Efficiently. Communicate Globally.

If implementing a Controlled English system for your organization’s technical publications efforts is something you’d like to explore, give Interpro a call. Our 30+ years of experience in translation, translation-related technology, and engineering of source content to be translated into multiple languages will help you determine whether or not this is something that would benefit your organization.

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