Jeg er overbevist.

• Jeg = I
• er = am / are / is (present tense of å være, to be)
• overbevist = convinced

So the structure is very close to English:

• Jeg = subject
• er = verb
• overbevist = subject complement / adjective-like description

That is why the sentence feels very familiar to an English speaker.

Because overbevist here describes your state, not an action you have done.

• Jeg er overbevist = I am convinced
• literally, you are in a convinced state

If you used har, you would usually be building a perfect tense, and that would mean something different. In this sentence, Norwegian works like English: you use to be + a describing word.

It is historically a past participle, but in this sentence it functions very much like an adjective.

That is common in both Norwegian and English:

• I am tired
• I am convinced

In Norwegian:

• Jeg er trøtt
• Jeg er overbevist

So for a learner, the most useful way to understand it here is: overbevist is describing jeg.

A simple learner-friendly approximation is:

• Jeg ≈ yai or yay
• er ≈ air / ehr, depending on dialect
• overbevist ≈ OH-ver-buh-VIST

A few pronunciation notes:

• j in Norwegian is usually like English y
• g in jeg is often weak or silent in many accents
• the stress in overbevist falls toward the end: -vist

Exact pronunciation varies by dialect, so do not worry if you hear different versions.

Yes. You very often add om or at.

Two common patterns are:

• å være overbevist om noe = to be convinced about something
• å være overbevist om at ... = to be convinced that ...

Examples:

• Jeg er overbevist om dette. = I am convinced about this / convinced of this.
• Jeg er overbevist om at han har rett. = I am convinced that he is right.

This is one of the most useful extensions of the sentence.

You put ikke after the verb:

• Jeg er ikke overbevist. = I am not convinced.

That follows the normal Norwegian pattern for simple main clauses:

• subject + verb + ikke

So:

• Jeg er overbevist.
• Jeg er ikke overbevist.

Yes. The same basic pattern works in other tenses.

Examples:

• Jeg var overbevist. = I was convinced.
• Jeg har vært overbevist. = I have been convinced.
• Jeg blir overbevist. = I am becoming convinced / I get convinced
• Jeg ble overbevist. = I became convinced / I was persuaded

This helps show an important difference:

• er overbevist = a present state
• ble overbevist = the moment or process of becoming convinced

It is natural and correct, but it can sound a little stronger or more formal than some everyday alternatives.

For example:

• Jeg er sikker. = I am sure.
• Jeg tror det. = I think so.
• Jeg er ganske sikker. = I am fairly sure.

Jeg er overbevist often suggests strong conviction. It is a good choice when you want to sound certain and definite.

They are similar, but not identical.

• sikker = sure / certain
• overbevist = convinced

Overbevist often suggests that your belief is based on reasons, evidence, or persuasion.
Sikker is broader and often more everyday.

Compare:

• Jeg er sikker på at det stemmer. = I am sure it is correct.
• Jeg er overbevist om at det stemmer. = I am convinced it is correct.

In many situations, both work, but overbevist usually sounds stronger.

The basic order is:

• Jeg
  • er
    • overbevist
• subject + verb + complement

That is the normal word order in a simple Norwegian main clause, and it matches English very closely.

If you add other words, Norwegian still keeps the finite verb early in the sentence:

• Jeg er helt overbevist. = I am completely convinced.
• Jeg er ikke overbevist. = I am not convinced.

So this sentence is a very good example of straightforward Norwegian word order.