Ef við hefðum haft stærri hjólbörur, hefðum við getað fært fleiri plöntur í einu.

It is a past counterfactual or unreal past condition.

The speaker is talking about something that did not happen, and imagining a different result:

Ef við hefðum haft stærri hjólbörur, hefðum við getað fært fleiri plöntur í einu.

This is the Icelandic equivalent of If we had had bigger wheelbarrows, we would have been able to move more plants at a time.

Because Icelandic normally uses the subjunctive in both halves of this kind of unreal conditional.

• hefðum haft = had had
• hefðum getað fært = would have been able to move / could have moved

Hefðum is the 1st person plural past subjunctive form of hafa.

So both clauses are marked as hypothetical, not factual.

It is a compound verb form built from:

• hefðum = past subjunctive of hafa
• haft = the non-finite form used with hafa

Together, hefðum haft means had had in a hypothetical sense.

So Ef við hefðum haft stærri hjólbörur means If we had had larger wheelbarrows.

Because Icelandic follows a verb-second pattern in main clauses.

The whole if-clause comes first:

Ef við hefðum haft stærri hjólbörur, ...

After that, the main clause begins, and its finite verb must come first in that clause:

hefðum við getað fært ...

If the main clause stood alone, it would be:

Við hefðum getað fært fleiri plöntur í einu.

So the word order changes because the if-clause takes the first slot.

This combines two ideas:

• geta = can / be able to
• færa = move / carry / transfer

So:

hefðum getað fært = would have been able to move

The sentence is not just saying that they moved the plants. It says they would have had the ability to move more plants, if the wheelbarrows had been bigger.

They are comparative forms.

• stór → stærri = bigger / larger
• margir → fleiri = more (for countable things)

So:

• stærri hjólbörur = larger wheelbarrows
• fleiri plöntur = more plants

A useful contrast:

• fleiri is used for countable nouns, like plants
• meiri is used for uncountable quantities, like water or time

Here plöntur is the direct object of færa, so it is in the accusative plural.

The dictionary form is planta.

In the plural, plöntur can be nominative or accusative, and here the verb tells you it is functioning as the object:

færa fleiri plöntur = move more plants

In this sentence, it is plural in meaning: the sentence is talking about larger wheelbarrows, not just one.

Also, hjólbörur is a word that often surprises learners because it is commonly encountered in a plural-looking form. So even if the meaning is clear, the form can feel unusual at first.

The safest approach is to learn hjólbörur as a whole vocabulary item and get used to seeing it in context.

Í einu is a fixed expression meaning:

• in one go
• at one time
• all at once

In this sentence, it means they could have moved more plants per trip or in one load.

It is best learned as a chunk: í einu.

Yes.

You could say:

Ef við hefðum haft stærri hjólbörur, þá hefðum við getað fært fleiri plöntur í einu.

Here þá adds a bit of then-style emphasis, like English then in If..., then...

But it is not necessary. The original sentence without þá is completely natural.

Because the sentence is talking about them indefinitely:

• larger wheelbarrows
• more plants

Icelandic does not use a separate word like English the. Instead, the definite article is usually attached to the noun.

So if the sentence meant the wheelbarrows or the plants, you would expect forms like:

• hjólbörurnar
• plönturnar

But here the indefinite forms are exactly what you want.