I would like to explain to a non-native girlfriend that it's correct to say "Where am I?" on its own as a question, but if you want to say "Can you guess where I am?" or "Do you know where I am?" or "I don't know where I am" then the word order is flipped around.
Although I am native I don't have any idea why this grammar is what it is, so I'd really appreciate any help explaining it.
The subject and auxiliary verb are normally switched order in a question. This process is called a subject-auxiliary inversion. That's why the auxliary verb precedes the subject in your first example.
Where am I?(NOT
where I am?)
However, when the question is embedded in a sentence(or inside another clause) this process does not occur.
Can you guess [Where I am]? (NOT
Can you guess where am I?)
[1] Where am I?
[2] Do you know [where I am]?
With main clause interrogatives like [1], the interrogative phrase usually occupies initial position and, if it is not the subject, its placement triggers subject-auxiliary inversion. But in subordinate interrogative clauses like the bracketed one in [2], there is normally no inversion.
Main clause interrogatives ask questions, but subordinate interrogative clauses (embedded questions) express questions, but do not themselves ask them.
Usually (but not always) the construction can be glossed with the formula “the answer to the question”. The meaning of [2] is “Do you know the answer to the question ‘Where am I?’”
You other examples fit the same pattern as [2].
The cause lies in the different syntax of both examples:
Where am I?
This is a simple main clause which comes in the form of a question. Therefore its word order differs from that of normal positive sentences: the predicate is moved in front of the subject to mark the sentence as a question.
Positive statement: You_[Subject] are_[Predicate] here_[Prepositional Object].
Question: Where_[Question word] am_[Predicate] I_[Subject]?
Now let's come to your second example, which is yet another question. Again, let's compare it to a positive statement like above:
Positive statement: I know where I am.
Question: Do you know where I am?
This time, we have a main clause and an (interrogative) clause, which is highlighted in bold print. As you can see, the subject-predicate-inversion to mark the question only happens in the main clause while the subordinate clause remains unchanged:
Positive statement: I_[Subject] know_[Predicate] where I am_[Object].
Question: Do_[Predicate1] you_[Subject] know_[Predicate2] where I am?_[Object]
So there you have it: Example 1 is just a main clause, which is why the word order is changed when forming a question. Example 2 is a combination of main clause and subordinate clause, so the word order only changes in the main clause to mark the sentence as a question.
For those who don't want a strict grammatical approach, this is how I'd explain (native English speaker to learner)
"Where am I" is a question. That's signalled by the reversal of "am" and "I".
"Can you guess [X]" is also a question, whatever [X] might be. A statement would be "You can guess [X]", without the reversal.
in "Can you guess where I am", [X] is "where I am". If I remember my grammar right, it's a noun phrase, and the object of the verb "guess" (but I'm not completely certain I do remember right ).
Where am I -> The place were you are | Where I am -> Were YOU are
They can mean the pretty much think, but they are used in differend ocasions, basicly
You can, for example say: The place were I am is beutiful; but you cant say The place were am I is beutiful;
You can say: Were am I from? And you can also say Were I am from. (but when you say this u are expected toadd more info to your phrase, like, Thats were I am from, or smthing like that)
