Ik lees een artikel over het klimaat.

Because Dutch verbs change form to match the subject in the present tense.

The infinitive is lezen = to read.

With ik (I), the present-tense form is usually the stem:

• lezen → stem lees
• ik lees = I read / I am reading

A quick present-tense overview:

• ik lees = I read
• jij leest = you read
• hij/zij/het leest = he/she/it reads
• wij lezen = we read
• jullie lezen = you read
• zij lezen = they read

So lezen is the dictionary form, while lees is the correct conjugated form here.

This is the normal word order for a simple Dutch main clause:

subject + finite verb + object + other information

So here:

• Ik = subject
• lees = finite verb
• een artikel = direct object
• over het klimaat = prepositional phrase giving more detail about artikel

Dutch is a V2 language, which means the finite verb usually comes in the second position in a main clause. In this sentence, the subject is first, so the verb comes right after it.

een here is the indefinite article, meaning a or an.

So:

• een artikel = an article

Dutch uses een for both a and an. There is no separate form depending on the next sound.

Be careful: een can also mean one as a number, but then it is usually stressed and often written één if needed for clarity.

So:

• een artikel = an article
• één artikel = one article

Because klimaat is a het-word in Dutch.

Dutch nouns usually take either:

• de
• het

You generally have to learn which article belongs with each noun.

So:

• het klimaat = the climate

A few useful points:

• Singular neuter nouns take het
• Most plural nouns take de, even if the singular takes het

So:

• het klimaat = the climate
• de klimaten = the climates

There is not always a logical reason visible from the form, so it is best to learn nouns together with their article:

• het klimaat
• het artikel

Here over means about.

So:

• een artikel over het klimaat = an article about the climate

This is a very common use of over when talking about a topic:

• een boek over geschiedenis = a book about history
• praten over politiek = to talk about politics

Be aware that over can also mean other things in different contexts, such as over/across in a physical sense, but in this sentence it clearly means about.

Usually yes, and in this sentence it does.

artikel can mean:

• a newspaper or magazine article
• an item in a law or contract
• a grammatical article, depending on context

In Ik lees een artikel over het klimaat, it most naturally means a written piece, such as a magazine, newspaper, or online article.

So this is a helpful cognate, but like many cognates, it can have a few related uses depending on context.

A learner often notices that een is not pronounced very strongly in normal speech.

• een is often pronounced something like uhn or a very reduced ən
• lees has a long ee sound: roughly like lace without the strong English glide, ending in s

A rough pronunciation of the whole sentence is:

ik lays uhn ar-ti-kul oh-vur hut kli-maht

That is only approximate, but it may help.

A few details:

• ik has a short vowel
• lees has a long vowel
• het is often pronounced weakly in natural speech, sometimes almost like ut

Yes. Dutch often uses the simple present where English might use either:

• I read
• I am reading

So Ik lees een artikel over het klimaat can mean:

• I read an article about the climate
• I am reading an article about the climate

The exact meaning depends on context.

If Dutch speakers want to emphasize that the action is in progress right now, they can also say:

Ik ben een artikel over het klimaat aan het lezen.

That is closer to I am reading an article about the climate, but the simpler sentence with ik lees is also completely normal.

Because het klimaat is a complete noun phrase meaning the climate.

Inside the phrase:

• het = the
• klimaat = climate

And that whole phrase is attached to over:

• over het klimaat = about the climate

So Dutch does not need any extra linking word there. It works much like English:

• about the climate

Not normally in everyday Dutch for this meaning.

Dutch can make compound nouns, but een artikel over het klimaat is the most natural way to say an article about the climate.

A compound like klimaatartikel might be understandable in some contexts, but it sounds more like a specialized label than normal everyday phrasing. For a learner, een artikel over het klimaat is the safe and natural choice.

Yes — absolutely.

It is very helpful to learn:

• het klimaat
• het artikel

instead of learning only:

• klimaat
• artikel

That is because Dutch articles are an important part of the noun, and you often cannot predict de or het reliably just from meaning.

Learning the full noun phrase will help with:

• correct article use
• adjective endings later on
• sounding more natural overall