STE is a controlled language with a controlled dictionary.

To help you use the approved words correctly, the dictionary gives approved alternatives for unapproved words. If you find an alternative that has the same part of speech, you can use that word to replace the unapproved word in the sentence (word-for-word replacement).

STE: A value of 2 mm is permitted.

When you replace a word, always make sure that the alternative you select does not change the meaning of the sentence. If the meaning changes, or if the alternative does not have the same part of speech, you must use a different construction.

This is because:
1. You must change the grammatical structure of the sentence to use the alternative that you selected. Usually, the approved examples show you how to do this.

Examples:
Non-STE: The oil level on the sight gauge must be visible during the test
STE: Make sure that you can see the oil level on the sight gauge during the test.

In this example, the approved verb “see” replaces the unapproved adjective “visible”. But to use the verb “see”, it is necessary to replace “must be” with “make sure that you can.”

Non-STE: Cycle the unit twice to remove air from the lines.
STE: Operate the unit for two cycles to remove air from the lines.

In this example, the approved noun “cycle” replaces the unapproved verb “cycle”.
When you use different constructions, always make sure that you use approved words that do not change the meaning of the sentence.

2. The word-for-word replacement of the unapproved word gives a meaningless result.

Example:
Non-STE: Without this modification, the service life of the unit can be uncertain.

示例：

“Uncertain” is not in the dictionary, but it means “not sure” or “not known”. Thus, you can refer to “sure” and “know” in the dictionary. You will find that they are approved and you can use “not sure” and “not known” (“not” + the approved word).

But do not write:
Without this modification, the service life of the unit cannot be sure.
or
Without this modification, the service life of the unit cannot be known.
These sentences do not make sense and they are not good English.

You must ask yourself what this sentence really means and then use a different construction.

Non-STE: Without this modification, the service life of the unit can be uncertain.
STE: Without this modification, it is possible that the service life of this unit will be shorter than usual.

The STE sentence uses approved words in a different way to give the same information clearly. Always make sure that you know what you want to say and that the words that you use give the meaning that you want.

3. The approved alternative that you find changes the meaning of the sentence.

Example:
Non-STE: Just apply very light pressure to the surface.
STE: Only apply very light pressure to the surface.
NOT: Immediately apply very light pressure to the surface.

“Immediately” is the approved alternative for “just”. But if you use the word “immediately” in this context, you will change the meaning of the instruction.

4. The word that you must replace is not in the dictionary.

Example:
Non-STE: The incidence of water in fuel is dangerous.
STE: Water in fuel is dangerous.

“Incidence” is not in the dictionary, so you must think of a different word that has the same meaning, for example, “presence”. But “presence” is not approved and its suggested alternative is “be”. You can use a different construction to keep the same meaning.

How to use a different construction

When you cannot do a word-for-word replacement, use different words to get the same result.

Example:
Non-STE: If the air intake flap has failed, deactivate air inlet valve.
STE: If the air intake flap is not serviceable, lock the air inlet valve in the fully open position
or
If the air intake flap is not serviceable, do the deactivation procedure of the air inlet valve.
NOT: If the air intake flap is not serviceable, disconnect (or stop, or isolate) the air inlet valve.

In this example, “deactivate” is not approved. The alternatives in the dictionary are “disconnect”, “stop”, and “isolate”. In some contexts, these alternatives are satisfactory.

But in this example:
- “Disconnect” is technically incorrect.
- “Stop” and “isolate” are meaningless.
Answer these questions before you write a sentence:
- “What is the meaning of the word “deactivate” in this context?”
or
- “What is the action that the reader must do?”

You will then understand that the “deactivation” is the result of an action: lock the air inlet valve in the fully open position. Thus, if you tell the reader to do that, your instruction will be correct and the reader will do the task correctly.

In the examples, you saw:
- How you can change an unapproved word in a sentence.
- How you can write a new sentence that has the same meaning.

Often you must select different words, use different verb forms or write completely new sentence constructions. Sometimes you must break long sentences into shorter ones, delete information which is not necessary, or ask an engineer for further explanation. And frequently you must fully reorganize your text. Then, when you change one part of a text, you must make sure that it has no negative effect on other parts of the text.

Example:

Non-STE: If cracks are detected during this procedure, the operator must perform the repair within a certain number of flight hours depending on crack length. Refer to the following table:

STE: If you find cracks, refer to the table that follows:

e) The instruction is not in the imperative form.

- “certain” with “some”. “certain” 为 “some”.

Thus, the sentence becomes:

If cracks are detected during this procedure, the operator must do the repair in some flight hours depending on the crack length. Refer to the following table:

This keeps the same construction, but it is not good English.

To replace “are detected” (unapproved verb and passive voice), you must change the construction to: “If you find cracks ...”. But this does not change the construction of the remaining part of the sentence.

To replace “following,” you must make a small change to the construction: “Refer to the table that follows:”

To replace “depending” you must make a major change to the sentence. This is because you cannot do a word-for-word replacement with the alternative given in the dictionary: “if”. (“If” what?).

You can then write the first sentence as follows:
If you find cracks during this procedure, do the repair before the number of flight hours applicable to the crack length.

But there are still 21 words and the technical meaning is not easy to understand. Also, part of the information is in the table. Thus it is not necessary to give it two times. A good solution is to put the instruction in the table heading, as shown in the STE version.

Always remember that the primary objective of STE is that readers immediately understand each sentence that they read.