When you look at Norwegian words and English words they are very similar.  In fact, you can often make out what a Norwegian word is by the way it looks, however, the sounds can be quiet different.

One of the major changes that occurred to the English language is known as the Great Vowel Shift.  This shift started around the 1400s and finished by the end of the 1700s.  When Norwegian (Old Norse) and English (Old English) started out they had similar vowel sounds, in fact, so did all the languages of Germanic Language family.  The sound box looked like this:

Above is a basic diagram of where the sounds where originally created in an Old English person’s mouth.  When the Great Vowel Shift finished the English vowel sounds had changed – they were now being created in a higher position in the mouth, as in the diagram below:

This meant that [a] turned from an ‘ah’ sound into an ‘ei’ sound and [e] turned from an ‘eh’ sound into an ‘i’ sound and so forth.  So English vowel sounds moved up and away from their Germanic origins.  However, Norwegian has basically kept the Germanic vowel sounds from the Viking Age.  This is why today you find a difference between the Norwegian and English vowel sound for [a] – katt (kaht) and cat (ceit).

So if you read English using the original vowel sounds from Old English you will likely sound very Norwegian.