Is "The customer experiences that the connection has been failed by unknown factor." grammatically correct?

Question

For this sentence:

"The customer experiences that the connection has been failed by unknown factor."

the following sound unnatural to me – but is it still grammatically correct?

• a. "The customer experiences that..."
  
• b. "...has been failed by..."

Answer 1

As for the customer experiences that, that is fine. You could change experiences to notices or finds, but that is not necessary.

As for has been failed, that is a different thing.

Strictly speaking I assume it could be grammatically correct, but I highly doubt the meaning is the one you want to convey.

You could use fail in the passive form like this:

The test was failed by the student.

This is an unusual way of saying:

The student failed the test.

Now, did your "unknown factor" fail the connection? Was the "unknown factor" trying to achieve the connection? I doubt it.

Normally, a connection does not get failed, it fails. So simply use the active form:

The connection failed due to an unknown factor.
The connection failed because of an unknown factor.

Factor is a bit hazy in this context, by the way. I would suggest that if you do not know what caused the connection to fail, just say you do not know the reason:

The connection failed for an unknown reason.

Answer 2

The customer experiences that the connection has been failed by unknown factor.

Your right, the original sounds unnatural. I see three problems, and you've correctly identified two of them. I'll address them each individually.

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The customer experiences that the connection has been failed by unknown factor.

I don't think experiences is a very fitting verb in this context. On a personal level, systems failures are something you observe, not experience. That said, this is a tricky one, because it is okay for a company to issue a statement saying:

We have experienced too many system failures over the past month.

because the speaker is talking from a corporate perspective, not a personal one. From a customer perspective, though, I'd say that customers can experience heartache, frustration, or disappointment, but not system failures, or lost connections. Instead, I would choose a verb such as notices or observes.

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The customer experiences that the connection has been failed by unknown factor.

This is the wrong verb tense. When a system crashes, and we use the verb fail, we say that it has failed, not that it has been failed. Once again, though, this is tricky, because we can say:

The system has been down for over two hours!

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The customer experiences that the connection has been failed by unknown factor.

I don't think by is the right preposition here. I think you are trying to say because of (or due to). If you want to stick with a preposition, use for instead of by.

Also, I think you need to put the word some in front of unknown factor, or else make it plural. When words such as reason or factor are in a prepositional phrase, we generally use some (or an indefinite article) when using the singular. For example, I might say either of these:

For some unknown reason, the connection was lost.
For unknown reasons, the connection was lost.

But I would not say:

For unknown reason, the connection was lost.

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Put all of these changes together, and we get:

The customer experiences notices that the connection has been failed by because of some unknown factor.

Or, without the crossed-out words:

The customer notices the connection has failed because of some unknown factor.

As mentioned previously, the phase due to could be used in place of because of.

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By the way, I agree with oerkelens; at the end of the sentence, I think reason or cause would be a better word than factor. My final edit would be:

The customer notices the connection has failed due to unknown causes.