Hi, there

Let's suppose I am writing a text about language verb aspects and tenses. Then I want to say that, even though verbs can morphologically or syntactically indicate a wide range of ideas (called here “aspects”) in many languages (habitual aspect, perfect aspect, etc), these aspects all follow some kind of logic and don’t randomly refer to any given concept in the outside world. They can refer to the completeness of an event, or to whether this event happened a long time ago or recently, or even if the event occurred to the speaker, the listener or to a third person in the discourse, but they will never refer to such random concepts as whether the event happened downriver or upriver or at which height above sea level the event occurred

So, let's suppose I write the following phrase:

"(...) For example, there must be no language in the world that expresses, on its list of grammatical patterns, the expectation that verbs should indicate the height above sea level for a event described."

I'd like to know if I can use "there MUST be no..." to mean "it is very unlikely that there is...". Can I use "must" to indicate possibility in this case? If not, could I say "There SHOULD be no.." to indicate that it is unlikely?... And another thing: would it sound odd to say "height above sea level for a event described", with "described" after "event"?

Thank you very much for your help!

Question

Hi, there

Let's suppose I am writing a text about language verb aspects and tenses. Then I want to say that, even though verbs can morphologically or syntactically indicate a wide range of ideas (called here “aspects”) in many languages (habitual aspect, perfect aspect, etc), these aspects all follow some kind of logic and don’t randomly refer to any given concept in the outside world. They can refer to the completeness of an event, or to whether this event happened a long time ago or recently, or even if the event occurred to the speaker, the listener or to a third person in the discourse, but they will never refer to such random concepts as whether the event happened downriver or upriver or at which height above sea level the event occurred

So, let's suppose I write the following phrase:

"(...) For example, there must be no language in the world that expresses, on its list of grammatical patterns, the expectation that verbs should indicate the height above sea level for a event described."

I'd like to know if I can use "there MUST be no..." to mean "it is very unlikely that there is...". Can I use "must" to indicate possibility in this case? If not, could I say "There SHOULD be no.." to indicate that it is unlikely?... And another thing: would it sound odd to say "height above sea level for a event described", with "described" after "event"?

Thank you very much for your help!

Answer

Erik's answer is great.

However in British written English "must" is perfectly fine and is probably what I would use. But only in writing.

Erik's alternatives are more likely in speech.

Answer

Using "must" here is a little awkward.

If you 100% know (because you checked every language) or you are will to assert it without leaving any doubt, you'd say simply:
"There's no language in the world that expresses..."

You can use "should" here, but it sort of implies that you are emphasizing in the statement that your assertion is a result of what you have already said previously:
"(Thus based on what I just said) There should be no language in the world that expresses..."

If you are simply asserting the very high probability that such a language doesn't exist, there are many ways to say this:
"It's doubtful there is any language in the world that expresses..."
"It's unlikely there is any language in the world the expresses..."
"I highly doubt there is any language in the world that expresses..."
"It's hard to imagine any language in the world that would express..."

As for the "event described" question.  What you wrote is correct English.  It might be a little smoother to say:
"...that verbs should indicate an event's height above sea level"

Hope this helps.