Ég véfengi stigafjöldann.

• Ég = I
• véfengi = a form of the verb vefengja = to dispute, question, challenge
• stigafjöldann = the point total / the number of points

So the sentence has the normal Icelandic order subject + verb + object.

Véfengi is a subjunctive form of vefengja.

That matters because Icelandic often uses the subjunctive where English might use something like would dispute, might dispute, or were to dispute, depending on context.

So if you are wondering why this feels a little less straightforward than a plain present-tense verb, that is the reason: the form itself carries a more hypothetical or less direct sense.

Because Icelandic does not always need a separate auxiliary like English would.

In a sentence like this, the verb form véfengi can itself express that kind of meaning. English usually needs an extra word, but Icelandic can build more of that meaning into the verb form.

In everyday modern speech, many speakers would often prefer myndi + infinitive, for example:

• Ég myndi vefengja stigafjöldann.

That is often the more conversational way to say the same basic idea.

The dictionary form is vefengja.

When you look up Icelandic verbs, you normally look for the infinitive, so that is the form you would search for in a dictionary.

Because it is a masculine singular definite accusative form.

The basic dictionary form is:

• stigafjöldi = point total / number of points

In this sentence it is the direct object of vefengja, so it appears in the accusative. With the definite article attached, that gives:

• nominative definite: stigafjöldinn
• accusative definite: stigafjöldann

So the ending is showing both:

1. the case
2. the fact that it means the point total, not just a point total

Because Icelandic usually attaches the definite article to the end of the noun instead of using a separate word.

So English:

• the point total

becomes Icelandic:

• stigafjöldann

The the is built into the ending.

Because Icelandic writes compound nouns as one word much more often than English does.

Here the word is built from:

• stig(a)- = of points
• fjöldi = number, total, quantity

So stigafjöldi literally means something like point-number or points-total, which English would normally express as number of points or point total.

It comes from stig = point.

In compounds, Icelandic often uses a linking form based on a genitive or plural-related stem. Here stiga- means something like of points.

So:

• stigafjöldi = number of points
• literally: points-number

This is very common in Icelandic compound building.

It is grammatical, but it sounds somewhat formal or bookish, especially because of véfengi.

A more everyday version would often be:

• Ég myndi vefengja stigafjöldann.

So if you meet Ég véfengi stigafjöldann in a textbook, it may be there partly to show you a particular verb form, not just the most casual modern wording.

Yes, Icelandic word order is flexible, but the sentence as given is the neutral order.

• Ég véfengi stigafjöldann. = neutral
• Stigafjöldann véfengi ég. = more marked, with emphasis on the point total

So the original version is the most straightforward way to present the sentence to a learner.