> if varða has -a in first person singular, should it be varð in the
> sentance or not? I'm unsure as you wrote it as varða.


No, 'varða' is the form you want. The "first person singular" of a
verb just means forms that go with "I".

varða.....ek varða "I guard, watch, defend" (various other meanings)
vernda....ek vernda "I protect, defend"

verja.....ek ver "I defend" (various other meanings)

hlífa.....ek hlífi "I protect, spare"

The first two both belong to the same class of verbs as 'kalla'.
These are easy to spot as Zoega's dictionary prints (að) after the
head-word of a entry to show if it belongs to this class.

http://norse.net.ru/ondict/zoega/index.html

'verja' goes like 'spyrja'. (Coincidentally, 'ek varða' could also
be the past tense of 'verja' and mean "I defended"!)

'hlífa' goes like 'doema'. Well, I hope that's not too confusing.
Please let us know if you have any more questions or if I've made a
complete mess of explaining this.

Llama Nom