Learn Icelandic: Ég vil ekki borga.

This is a very important exception! While most verbs in Icelandic need að before the next verb (like ég þarf að borga for 'I need to pay'), the verb vilja (to want) connects directly to the next verb without að.

Why does ekki come between vil and borga?

In Icelandic, the negative word ekki normally comes right after the conjugated verb (here, vil). The second verb, which is the infinitive borga, gets pushed to the end of the clause.

Is vil an irregular verb?

Yes, vilja is irregular. The dictionary form is vilja (to want), but the 'I' form drops the ending to become simply ég vil. It doesn't follow the normal pattern where the 'I' form ends in a vowel.