I'm not sure if(or, whether) we can do it.
Can this sentence be written in this way…
I'm not sure can we do it.
Can whether, or if, be omitted like that and still be understandable?
Thanks.
Learn English – Omitting whether (if): Not sure if we can do this
subject-verb-inversion
Related Solutions
Everybody learns that What is the right way? is a Wh-Question structure. Add the intonation (which is what the question mark is for), and the context, and it's ordinary. As a question. It's formed from something like The right way is X, where the unknown X becomes what.
But as the Object Complement of a mental or communicational predicate, like know, be sure, or say, it's embedded in the sentence, rather than being the sentence. That makes it an Embedded Question (aka Headless Relative or Wh-Clause), and that's a standard complement type, with slightly different syntax from ordinary questions.
The slight difference is that the normal Question-Formation rule inverts the Subject and the first auxiliary verb
[with two caveant:
- be is always an auxiliary verb
- if there isn't an auxiliary verb, invoke Do-Support]
while an Embedded Question normally does not invert.
- Where are they? ~ I'm not sure where they are.
But, just in case the sentence is intended by the speaker to request information (rather than to merely comment on one's mental deficiency), one way of many that this indirect request can be signalled as a question is to use the other question structure, the one that actually resembles a question, with inversion, instead of without inversion.
- I'm not sure where are they. (means "Where are they?")
This is frequently intoned like a question instead of a statement, and punctuated with ? to mark this.
And that has become a very widespread pragmatic convention in the last 40 years or so, though it still varies locally and socially. And that's all, really. Both are correct, though they don't mean the same thing, pragmatically.
No, it is not valid (well, natural) English to say or to write:
- No, ∗sure I am not.
It would be understood, but it doesn’t sound at all right. It would mark you as a non-native speaker.
The closest to what you are talking about would be the very archaic and/or poetic-sounding full inversion:
- No, sure am I not.
I suppose you could say that if you really wanted to, but it sounds completely affected. It really stands out. It’s not normal speech, although neither is it “illegal” as your first one nearly is. Maybe you could use something like this for the very rare and special occasion:
- No, “certain” is very most definitely something that I am not!
That doesn’t sound normal either, but it might be used to draw attention to the first word. Regular speech would simply be:
- No, I’m not sure.
or sometimes,
- No, I’m not sure, either.
Or if someone else had just said that they weren’t sure, then you could respond with and of:
- No, I’m not, either.
- I’m not, either.
- Neither am I.
Notice the inversion in the last one.
Notice also how unlike in German, you cannot in English use “too” or “also” in the negative: you must use “not . . . either”, or less commonly “neither” followed by subject–verb inversion (that is, verb–subject). This last point I mention because is a very common mistake that native speakers of German often make in English, and some possible answers to your question might lead you down the wrong path.
Best Answer
Consider first this question on omitting "that" from a sentence. As the answer says, we can omit it when it is used as a subordinating conjugation, though there are some cases where it remains either necessary or clearer (this article has more advice on that).
Now, having considered that, consider that when we change from:
To:
In the result we don't really have an omitted that. What we have is an independent and a dependent clause conjoined together by nothing. Granted in this case that is the only English word that could do the job, but that doesn't really make any difference; if English had a million such words, or if someone's idiolect meant they often used que there, the result would be the same.
So really the phenomenon isn't that we can omit "that" at all, but that we can omit subordinating conjunctions.
In the examples you give here, if and whether are being used as subordinating conjunctions. And so they can be omitted similarly:
Now, we can't say looking at that whether it was if, whether or that which was omitted, again because it wasn't really any of them; we have subordinating conjunction happening without a word doing the task. The meaning is the same either way (and if not, that's a clear sign that you don't have a case where the omission is safe). Dropping if and whether here follows the same restrictions as mentioned in the two links above for that.
Inversion does something completely different:
This doesn't mix in with the omission of if or whether because it doesn't work without the omission:
You could combine the two clauses with a comma or full stop, but then it's something different again:
This is not an omission of the subordinating conjunction; it is making the two clauses more fully separate so while it arrives at something grammatical, the meaning is completely different.