Jag skriver en snabb anteckning med min penna på ett papper.

Swedish nouns belong to two grammatical genders:

• en-words: common gender
• ett-words: neuter gender

So:

• en anteckning = a note
• ett papper = a paper / a sheet of paper

This is something you usually have to learn together with the noun. It does not always match natural gender or logic from English.

A few more examples:

• en bok = a book
• ett bord = a table

Because snabb is an adjective describing anteckning, and anteckning is an en-word in the singular indefinite form.

Adjective endings in Swedish often work like this:

• en noun: snabb
• ett noun: snabbt
• plural: snabba

So:

• en snabb anteckning = a quick note
• ett snabbt meddelande = a quick message
• snabba anteckningar = quick notes

If you used snabbt here, it would not agree with anteckning.

In Swedish, possessive words like min, mitt, and mina usually replace the indefinite article.

So you say:

• min penna = my pen
• not en min penna

This is similar to English, where you say my pen, not a my pen.

The possessive must match the noun:

• min for most singular en-words
• mitt for singular ett-words
• mina for plural

Examples:

• min bok = my book
• mitt hus = my house
• mina böcker = my books

Here med means with in the sense of using something as a tool.

So med min penna means:

• with my pen
• using my pen

This is the normal way in Swedish to express the instrument you use.

Examples:

• Jag skriver med en penna. = I write with a pen.
• Han äter med en gaffel. = He eats with a fork.

Because you write on the surface of paper, not in it.

So Swedish uses på:

• på ett papper = on a piece of paper / on a sheet of paper

Compare:

• på bordet = on the table
• på väggen = on the wall

Using i would suggest being inside something, which does not fit here.

Good question. In Swedish, papper can mean both:

• paper as a material
• a paper / a sheet of paper as a countable item, depending on context

In this sentence, ett papper means a piece/sheet of paper.

Compare:

• Jag skriver på ett papper. = I am writing on a sheet of paper.
• Papper är dyrt. = Paper is expensive.

So the article ett makes it countable here.

Skriver is the present tense of skriva = to write.

So:

• jag skriver = I write / I am writing

Swedish present tense is often formed by adding -r to the verb stem or infinitive pattern, but the exact form depends on the verb.

Examples with skriva:

• att skriva = to write
• skriver = write / am writing
• skrev = wrote
• skrivit = written

Also, Swedish does not usually separate I write and I am writing the way English does. The same present form can cover both meanings.

This is the normal basic Swedish word order:

Subject + verb + object + other information

So:

• Jag = subject
• skriver = verb
• en snabb anteckning = object
• med min penna = how/with what
• på ett papper = where/on what

Swedish main clauses usually follow the V2 rule, which means the finite verb comes in the second position.

In this sentence, the subject comes first, so the verb naturally comes right after it.

For example, if you move another element to the front, the verb still stays second:

• På ett papper skriver jag en snabb anteckning.

That is more marked in style, but grammatically correct.

Literally, snabb describes anteckning, so it means a quick note.

In English, quick note can mean:

• a short note
• a note made quickly

Swedish can allow the same kind of idea, but if you want to be very clear that the action is quick, you would often use the adverb snabbt with the verb:

• Jag skriver snabbt en anteckning. = I am quickly writing a note.

So:

• en snabb anteckning focuses on the noun
• skriver snabbt focuses on the action

Sometimes, but not naturally in this exact version.

In this sentence, the articles help show that you mean:

• a quick note
• a sheet/piece of paper

So en snabb anteckning and ett papper are both natural.

If you remove them, the meaning changes or sounds less natural:

• Jag skriver anteckning is usually not correct in standard Swedish for this meaning.
• Jag skriver på papper can exist, but it means something more general like I write on paper or in writing/on paper rather than digitally, not necessarily on a sheet of paper.

So here the articles are doing real work.

Penna is the normal general word for pen.

It can refer to:

• a ballpoint pen
• a felt-tip pen
• sometimes a pen more generally, depending on context

If you want to be more specific, Swedish can do that too:

• kulspetspenna = ballpoint pen
• bläckpenna = ink pen / fountain pen

But in a sentence like this, penna is completely natural and general, just like pen in English.