[Closed] Grammar question

If means it is conditional. If X is true then Y would/will/is ....  'That' states a fact.

I'd have thought that the first is saying you 'know X to be true'.

The second is either conditional, saying that 'we know if X is true, [then Y happens]', or that there's some dispute over X being true, but 'they' know that it is.

The second doesn't seem to read correctly though.

“We know if X is true” is just pedantically sloppy grammar I think.

Though you could perhaps argue that it's a conditional reply.  "Do we know Y is true?" - “We know if X is true”.  Ergo, if X is true then Y is also true.  But TBH that's a reach.

"We know X is true"

The second example makes no sense to me.

Compare the second with:

We don't know if what he said is true

If (or whether) is used when two possibilities exist . In the above sentence, the second possibility is the implied "or not".

"We know..." has no second possibility.

We know that he dies in the end.

vs

We know if he dies in the end.

The latter is equivalent to:

We know if he dies in the end or not, but we aren't telling you.

"We know that if X is true. "

As written the first sentence is correct.

The second sentence makes no sense unless it's part of a larger sentence.

“We know that if X is true. ”

It would still need at least a comma to make sense..

“We know that, if X is true.”

“We know that if X is true then *something*”

"That" is demonstrative

"if" is conditional

In the first sentence "That" becomes the relative clause that introduces the noun. In the second "If" is consequential (conditional past present or future) specifying what follows;. (If that, then this)

A comma just indicates where you pause for a breath surely, so no need for one in a short sentence.

😂

“We know if X is true” suggests to me that previously you didn’t know if X was true or not and now you have added some measure/test to tell you.

A comma just indicates where you pause for a breath surely, so no need for one in a short sentence.

A panda eats shoots and leaves.

Good panda, eating its dinner..

A panda eats, shoots and leaves.

The second sentence infers that the panda robs fast food joints lol!

Or my personal favourite...

I helped my uncle Jack, off a horse.

I helped my uncle Jack off a horse.

Helpful nephew or into beastiality?

Commas are important.  😀

I helped my uncle Jack off a horse.

Commas are important.

Capitalisation clarifies it here.  Jack vs. jack.  "I helped my uncle Jack, off a horse." is poor grammar, that comma is superfluous.

I helped my uncle Jack off a horse.

A panda eats, shoots and leaves.

There seems to be a common thread here 😉  🙂

Capitalisation clarifies it here.  Jack vs. jack.  “I helped my uncle Jack, off a horse.” is poor grammar, that comma is superfluous.

Yeh I know, but it's funnier though. 😀

There seems to be a common thread here

The Panda is now a registered sex offender and can't go within 200 yards of a school.

Poor thing, he was only trying to eat his dinner..

The Panda is now a registered sex offender and can’t go within 200 yards of a school.

Poor thing, he was only trying to eat his dinner..

🙂

Its as you said in the OP - swap the words slightly:

We know that Poly is male.

We know if Poly is male.

We know if Poly is male.

Again, the second sentence requires additional context, it makes no sense on it's own.

I wonder if what molgrips is getting at is that the ‘if’ sentence implies a future event or perhaps an uncertainty about what is going to happen

i.e. We know that he dies in the end

vs we (will) know if he dies in the end.

It implies a future event but there's no context, so as a standalone sentence it's meaningless.

“We know if X is true”

The sentence implies future tense, but doesn't include "will" (or "we'll") and so makes little sense. It could imply a condition but needs "that" but isn't in either case the full sentence

Mattyfez - no it makes perfect sense.  It says “we” know the answer to the (unasked) question, however we aren’t actually telling you.  That might be a strange thing to do - but there are times it is the correct grammar.

What I want the second sentence to mean is X is a known quantity, without indicating what it is.

And yes of course in normal circumstances this would be trivial to rearrange to clarify which is what I'd do normally, but these are not normal circumstances. I'm building a vocabulary for sort of pseudo code.

Also, it needs to be the same in Dutch....

Spandau Ballet are your friends here.

We know this x is true.

I’m building a vocabulary for sort of pseudo code.

This puzzles me even further.  I can't (immediately) think of a usage for a code block that runs only if we know whether X is true or not (which seems to be the implied difference between the two forms).  Surely you'd just test X and act accordingly or run the code block anyway and manage if you're passed an X that is neither true nor not true (Schrodinger's X ? 🙂 ) .

Computers and business analysts seem to demand an IF <x is true> THEN <something> construction,

but humans don't.

Humans can say "If it rains, wear a coat"; they don't have to say "If it rains, then wear a coat". But that construction often makes its way to written English.

That's all I have to offer, hope it helps.

I'd know if X were true. I'm an Xpert.

Let’s eat grandma

Let’s eat, grandma

“We know if X is true”

We're that awesome you see, we have that capability, just show us X and we'll tell you straight away.

edit: oh, I see I'm a drip under pressure and Nico is the unknown quantity.

This puzzles me even further.  I can’t (immediately) think of a usage for a code block that runs only if we know whether X is true or not (which seems to be the implied difference between the two forms).

Tri state logic, implemented using a Boolean object in Java.  Because it's an object reference it can be true, false or null which means unknown or in this context, not supplied by the user.  Yes, I know it's a bit of a bastardisation and we should be using an enumeration, but the semantics are exactly the same ultimately.

A null pointer exception is thrown if you test it and it's null.  So you have to check for null explicitly  But these people (not me) have created logic with if/then/else statements in it because they weren't really thinking it through.  The required behaviour according to Wikipedia is called Kleene logic.  So if one of the values of an and statement is unknown then the result is unknown.

So what I have is like this effectively:

if X is known then

(if X is true then Y else Z)

Except X is something like 'customer is a premier customer' so we have:

if it is known if the customer is a premier customer then

(if the customer is a premier customer then Y else Z)

I suppose I could change it to 'if it is known wether or not the customer is a premier customer' but that's pretty wordy..

Does Java have anything similar to the C++ std::optional concept? Its use-case is exactly what you are describing.

Without such a construct you will have to have some form of validity check wherever you access the data.

I'd write the initial check as: "Is the data valid?" to handle the implementation language requirements then whatever tests are required by the business logic.

Oh, what's a castrated tup got to do with all this? "whether" vs "wether" 😉

I suppose I could change it to ‘if it is known wether or not the customer is a premier customer’ but that’s pretty wordy..

But less ambiguous, I think, to a human reader (as per the discussion above).  I see your point now, but surely it's more straightforward to simply call out something like "Do I know whether it is a premier customer yet?" and build on from that as a yes/no.  I assume if it's undef at that stage we'll need to find that out before the rest of the logic will make much sense because if it's irrelevant to the next steps why do we even care? 🙂

Interesting, anyway.  But glad I don't have to do it - vulgarisation of the logic for people that otherwise don't have any (and possibly don't even understand the subtleties of human language either) doesn't make for an easy task, I imagine. :O

Calling out the differences between the way humans talk and code needs to be written is a large part of my job 🙂 and they think I am being pedantic. It is quite fun asking them the right question though and seeing them realise how much they've taken for granted.

The only thing we truly know about X is that "he's gonna give it to ya!"