Discussion Groups / English Usage / January 2009

Your sequence of tenses is off.   Either "is" should be "was" or
"could" should be "can."  I'll disregard this in further discussion.

This is not the same as a), and it is meaningless in ordinary
English.  "Even if" implies a comparison between what the sentence
describes and what it does not describe.  In the case of "alive or
dead," it suggests that the subject of discussion can be either alive
or dead and implies that some third state of being might allow a
change.  But in ordinary speech one can only be alive or dead (let's
not get into near-death experiences and the like), so the "Even if"
clause covers everything and there is nothing to which "alive or dead"
can be compared to.  "Whether" contrasts alive against dead.  "Even
if" contrasts the two of them combined against other, nonexistent
states of being.  That's literal nonsense.

This is incorrect, because "if" cannot substitute for "whether" in
this case.  You wind up with the same problem you have with b).  The
ordinary use of "if" for "whether" occurs in reporting and implies an
actual choice: "I asked if I he would prefer potatoes or rice."
"Whether" is almost always better in such cases.