Meiri skilningur hjálpar okkur að vinna saman.

Because meiri has to agree with skilningur in gender, number, and case.

• skilningur is masculine
• singular
• nominative here, because it is the subject of the sentence

So the comparative adjective must also be masculine singular nominative: meiri.

A useful comparison:

• meiri skilningur = more understanding / greater understanding
• meira is used in other forms, for example with neuter words or as an adverb

Also, meiri is the comparative form of mikill (big, much, great).

Literally, it means more understanding.

In natural English, depending on context, it could also be understood as:

• greater understanding
• better understanding
• more mutual understanding

Here:

• meiri = more / greater
• skilningur = understanding

So the phrase is saying that an increase in understanding has a helpful effect.

Skilningur is the nominative singular form of the noun.

The ending -ur is a very common nominative singular ending for masculine nouns in Icelandic. In this sentence, skilningur is the subject, so the nominative is used.

So:

• skilningur = understanding as the subject
• if it appeared in another grammatical role, the form could change

This is one of the basic things learners notice in Icelandic: nouns often change form depending on case.

Hjálpar is the present tense, 3rd person singular form of the verb hjálpa (to help).

So:

• hjálpa = to help
• hjálpar = helps

It matches the subject meiri skilningur, which is singular:

• Meiri skilningur hjálpar ... = More understanding helps ...

Because the verb hjálpa takes the dative case in Icelandic.

That means the person being helped is not in the nominative form:

• við = we (nominative)
• okkur = us (dative/accusative form, and here specifically required because hjálpa governs the dative)

So:

• hjálpar okkur = helps us

This is very important in Icelandic: many verbs require a specific case for their object, and hjálpa is one of the classic examples.

Here að is the infinitive marker, similar to English to.

So:

• að vinna = to work

In the sentence:

• hjálpar okkur að vinna saman = helps us to work together

In everyday English, we often omit to after help and say helps us work together, but Icelandic still uses að here.

Here it means work.

That is a very common learner question, because vinna can mean:

• to work
• to win

The context tells you which meaning is intended.

In this sentence:

• að vinna saman = to work together

It would not make sense here as to win together.

Saman means together.

So:

• vinna saman = work together

Its position at the end is completely normal. Icelandic often places adverbs like this after the verb or verb phrase.

So the structure is very natural:

• að vinna saman = to work together

Because Icelandic does not always use a definite article where English might, and in this sentence the phrase is indefinite anyway.

Meiri skilningur means:

• more understanding
• greater understanding

not:

• the more understanding
• the greater understanding

The sentence is talking about understanding in a general sense, not a specific previously mentioned understanding.

Yes, fairly similar.

The sentence breaks down like this:

• Meiri skilningur = subject
• hjálpar = verb
• okkur = object-like dative pronoun
• að vinna saman = infinitive phrase

So the overall order is close to English:

• More understanding helps us to work together

That makes this a fairly approachable sentence for an English speaker, even though the case system is different.

Yes. That is a very good translation.

Possible English translations include:

• More understanding helps us work together.
• Greater understanding helps us work together.
• Better understanding helps us work together.

The most literal is probably:

• More understanding helps us to work together.

But in natural English, greater understanding often sounds a bit smoother.

Here are the dictionary forms:

• meiri → comparative form of mikill (much, big, great)
• skilningur → understanding
• hjálpar → from hjálpa (to help)
• okkur → pronoun form from við (we/us)
• að → infinitive marker to
• vinna → to work / to win
• saman → together

This is a useful way to study the sentence, because several words are not appearing in their most basic dictionary form.

A rough learner-friendly guide is:

MAY-ri SKIL-ning-ur HYAL-par OCK-ur ath VIN-na SA-man

A few pronunciation notes:

• ei in meiri sounds roughly like ay
• hj in hjálpar is a special Icelandic sound; English speakers often approximate it as hy
• ll is not in this sentence, but many learners expect strange spellings elsewhere in Icelandic
• ð in að is a soft sound, somewhat like th in this
• stress usually falls on the first syllable of Icelandic words

That said, listening to native audio is much better than relying only on English-style spelling guides.