I just looked at what you were responding to. Arika Okrent (I know her) is a
serious linguist and knows what she's talking about.
Cleary, the whole disyllable "O say" is the vocative element (which has also
been interpreted as "José"). The entire first quatrain is a single sentence,
a question:
O say can you see, by the dawn’s early light,
What so proudly we hail’d at the twilight’s last gleaming,
Whose broad stripes and bright stars through the perilous fight
O’er the ramparts we watch’d were so gallantly streaming?
The next two lines affirm that you should be able to:
And the rocket’s red glare, the bombs bursting in air,
Gave proof through the night that our flag was still there,
while the last two lines reiterate the question:
O say does that star-spangled banner yet wave
O’er the land of the free and the home of the brave?
The second stanza is still uncertain for the first half
On the shore dimly seen through the mists of the deep
Where the foe’s haughty host in dread silence reposes,
What is that which the breeze, o’er the towering steep,
As it fitfully blows, half conceals, half discloses?
and finally gives the definitive answer.
Now it catches the gleam of the morning’s first beam,
In full glory reflected now shines in the stream,
’Tis the star-spangled banner—O long may it wave
O’er the land of the free and the home of the brave!
The third stanza goes on to a different question:
And where is that band who so vauntingly swore,
That the havoc of war and the battle’s confusion
A home and a Country should leave us no more?
but in only three lines, then answers:
Their blood has wash’d out their foul footstep’s pollution.
No refuge could save the hireling and slave
From the terror of flight or the gloom of the grave,
And the star-spangled banner in triumph doth wave
O’er the land of the free and the home of the brave.
Finally, it ends with the peroration that might have done better as the anthem
than the first stanza:
O thus be it ever when freemen shall stand
Between their lov’d home and the war’s desolation!
Blest with vict’ry and peace may the heav’n rescued land
Praise the power that hath made and preserv’d us a nation!
Then conquer we must, when our cause it is just,
And this be our motto – “In God is our trust,”
And the star-spangled banner in triumph shall wave
O’er the land of the free and the home of the brave.
Recently the ambiguity in the fourth line was discussed: is "us" an indefinite
object -- the nation was made and preserved for us -- or a direct object --
the pow'r made us into and preserved us as a nation.