Ég held að þessi runni hafi blómstrað fyrr í fyrra.

That is a very common question. The verb halda does often mean hold, but in the fixed expression halda að ... it means think / believe / suppose.

So:

• Ég held að ... = I think that ...
• Hún heldur að ... = She thinks that ...

This is an idiomatic use of the verb, so it is best learned as a chunk: halda að = to think / believe that.

Here að is a conjunction meaning that. It introduces the clause that contains what the speaker thinks:

• Ég held = I think
• að þessi runni hafi blómstrað fyrr í fyrra = that this bush bloomed earlier last year

It is not the infinitive marker here. In English, that is often omitted, but in Icelandic að is very commonly kept.

Þessi means this, and it has to agree with the noun in gender, number, and case.

Here:

• runni = bush / shrub
• it is masculine singular nominative
• so the matching form is þessi

That gives þessi runni = this bush.

Also, Icelandic normally does not use the suffixed definite article when a demonstrative is already present, so you say þessi runni, not normally þessi runninn.

Runni is in the nominative singular because it is the subject of the subordinate clause:

• þessi runni hafi blómstrað ...
• this bush has/had bloomed ...

Subjects are normally in the nominative in Icelandic, just as they are conceptually in English even though English no longer marks case much on nouns.

Hafi is the present subjunctive form of hafa.

In a sentence like Ég held að ..., Icelandic often uses the subjunctive in the following clause to show that this is the speaker’s belief, judgment, or assumption rather than a flat statement of fact.

So:

• hefur = indicative present
• hafi = subjunctive present

In this sentence, hafi blómstrað is a normal way to express what the speaker thinks happened. For an English speaker, the key idea is that the mood is doing important work here: it marks the clause as something believed or inferred.

It is a perfect-type construction:

• hafi = subjunctive of hafa (to have)
• blómstrað = the verb form used after hafa from blómstra (to bloom / flower)

So hafi blómstrað means roughly has bloomed / bloomed, depending on context.

A useful thing to know is that Icelandic and English do not always use perfect forms in exactly the same places. Because the sentence contains í fyrra (last year), English will usually prefer bloomed, even though Icelandic uses hafi blómstrað.

Learners often think of it that way, and that is a helpful first approximation. More specifically, in Icelandic grammar this form after hafa is usually called the supine (sagnbót).

So in:

• hafi blómstrað

blómstrað is the form required after hafa in this perfect construction. It does not agree with runni in gender or number here.

Because the sentence is built as a subjunctive perfect clause: hafi blómstrað, not a simple past clause.

That choice fits well after Ég held að ..., where the speaker is presenting an opinion or inference about a completed event. English may translate this with a simple past, but Icelandic often uses this kind of construction where English would not.

So the difference is not just tense; it is also about mood and how the speaker presents the information.

They are related in form, but they do different jobs here:

• fyrr = earlier / sooner
  This is a comparative adverb.
• í fyrra = last year
  This is a fixed time expression.

So:

• fyrr í fyrra = earlier last year

That is why the sentence is not repeating the same word by accident. It is using two different expressions that just happen to look similar.

Yes. Í fyrra is the standard way to say last year.

It is best learned as a chunk:

• í fyrra = last year
• á þessu ári = this year
• á næsta ári = next year

Even though fyrra comes from the same family of words as earlier / former, the whole phrase í fyrra simply means last year.

Yes, usually it does. Fyrr means earlier, so it normally suggests some comparison point, even if that point is not stated explicitly.

Depending on context, fyrr í fyrra could mean:

• earlier than expected last year
• earlier than usual last year
• earlier than some other event last year

The exact comparison has to come from context.

Because this is a subordinate clause introduced by að.

In main clauses, Icelandic often follows a verb-second pattern. But after a conjunction like að, the clause normally has more straightforward subordinate-clause word order:

• að
  • subject
    • finite verb
      • other material

So:

• að þessi runni hafi blómstrað fyrr í fyrra

is exactly the kind of order you should expect.

It is fairly close, but not perfectly one-to-one.

A very literal breakdown would be:

• Ég held = I think
• að = that
• þessi runni = this bush
• hafi blómstrað = has/had bloomed in a subjunctive perfect sense
• fyrr í fyrra = earlier last year

The main differences from English are:

• Icelandic keeps að where English often drops that
• Icelandic uses the subjunctive
• Icelandic uses a perfect-type form where English usually prefers a simple past because of last year