English grammar question involving conditional tense.

Am…..you’re speaking in the present tense.

Thank you. Conditional weirds me out sometimes.

Conditionals are not tenses!

@plethora is right, but not for the reason they state. Conditionals express some kind of counter-factual assertion. In this case, your sister doesn’t know how far from home you are. In this situation, the most common pattern is, as you correctly use, the past simple form of the verb – “knew”.

What is, in fact, confusing you is the form of the verb in the clause reporting what your sister does (or doesn’t) know – it is possible to use either “was” or “am” here, but not “were” (as there no counter-factual statement being made) – you are far from home; this is not the counter-factual statement.

The issue is one of whether you should use the present or past form of the verb in reporting clauses. Generally speaking, I suggest to my ESL students that one uses the past when there is some degree of doubt over the veracity of the reported statement or it relates a past event.

Think about it – remove the condition, and which one seems more natural?

> She knows how far from home I was right now.

or

> She knows how far from home I am right now.

Compare:

> She lied to him about how far from home I was.

and

> She lied to him about how far from home I am.

Cf. epistemics and modality

@the100thmonkey is right. Were wouldn’t be right in this case because “how far I ___ from home” is not the subjunctive statement; “if she knew” is the subjunctive statement. Compare if the sentence had been:

My sister would disown me if she WERE aware of how far from home I WAS. Whether that last word is “am” or “was” depends on how past you want the sentence to sound. Since you’re keeping it present, it would probably be “am”. But either is correct.

In full agreement with the above explanations and just restating:

“My sister would disown me if she knew X.”

All the conditional part (i.e., subjunctive mood, not tense) is there in that portion, without the X. The X is just a thing to be known. And that’s just stated in the tense and mood (indicative, not subjunctive) appropriate to the thing.

X could be
– which candidate I voted for (past – prior action)
– what I took from her dresser (past – prior action)
– how much I spent on this haircut (past – prior action)
– that I’ve decided I love broccoli (past and present)
– that I’m failing chemistry (present)
– who I’m with right now (present; we won’t insist on “whom” here in casual speech)
– what I’m going to do this afternoon (present)

You could also use any such statements in a different formula, nonconditional (indicative):

“My sister will laugh when I tell her X.”

“My sister was amazed when I told her X.”

X does not affect the mood and tense of the verbs in the main clause. That’s where the conditionality is, and not in the X.

Am. The “would” in your sentence is still in the present tense.