The general rule is that one syllable adjectives take -er (though there are cases where more
is also used). So duller
. In this case it seems pretty definitive. I fed both into the Cobuild Concordancer
and got no examples at all of more dull
, but lots of duller
. Here are a few :
a)... The female has duller
, brown plumage, and tends to skulk in the
b)... lost their nerve and gave the job to safer duller
architects" is inaccurate.
c)... the original Ford Escort, which had a much duller
it does today.
d)... about rugby have grown correspondingly duller
e).... on my evening visit I found the Poissonnerie even duller
f)... few of us could find anyone duller than
the prissy John Gummer MP -
g)...when you just look at it but it is actually a duller
h)...they are so much more noticeable during the duller
months of the year.
There are a couple of other interesting things about this sentence, and I hope you don't mind if I refer to them. Dull :
Notice that dull
here has a range of meanings from "not a bright colour" (a, g and h) to "boring" (the others). These meanings often overlap, as possibly in (a) or (h).
However, referring to a person it can also mean unintelligent
, and your sentence is therefore ambiguous - are you saying that he's boring or that he's stupid? For this reason, dull
is often avoided when we mean boring, unless the context makes the meaning clear - as in example (f). than I
: This form is possible, but unusual. The use of the subject pronoun after than is generally considered a mark of formal style, and to me sounds archaic. In everyday speech we would either add the operator*, or use the object pronoun. So : He is duller than I am
or He is duller than me
In fact, I'd say the construction with the subject pronoun is virtually non-existent. Again, the concordancer brought up no examples at all, and invented ones -like : She can swim better than he
or We work harder than they
. - sound very odd. They would normally be :
- with the object pronoun : She can swim better than him
, We work harder than them
-with the operator : She can swim better than he can
or We work harder than they do
* the operator is the verb in the phrase which would be used to make questions, negatives etc
Hope that helps.