Moja przełożona wysłała mi nowy grafik na przyszły tydzień.

Because moja has to agree with przełożona in gender, number, and case.

• przełożona is feminine singular
• so the possessive pronoun is moja = my for a feminine noun

Compare:

• moja przełożona = my female supervisor
• mój przełożony = my male supervisor

This kind of agreement is very common in Polish.

Przełożona means female superior / supervisor / manager / boss, depending on context.

It comes from the pair:

• przełożony = male superior
• przełożona = female superior

In a workplace sentence like this, English translations could be:

• my supervisor
• my manager
• my boss

It is a bit more formal or neutral than words like szef / szefowa.

Because Polish past tense agrees with the gender and number of the subject.

Here the subject is moja przełożona, which is feminine singular, so the verb is:

• wysłała = she sent

Compare:

• wysłał = he sent
• wysłała = she sent
• wysłali / wysłały = they sent

So the ending -ła tells you the subject is feminine singular.

This is a question of aspect.

• wysłać → perfective
• wysyłać → imperfective

In the sentence, the action is viewed as completed: the supervisor sent the schedule. That is why Polish uses the perfective past:

• wysłała

If you said wysyłała, it would suggest something like:

• she was sending
• she used to send
• she kept sending

That does not fit as well here, because this is a single completed action.

mi is the dative form of ja in its short, unstressed version.

Here it means:

• to me

So:

• wysłała mi = sent me / sent to me

The full stressed form is mnie, but mi is very common in ordinary sentences.

Compare:

• Dała mi książkę. = She gave me a book.
• Mnie dała książkę, nie tobie. = She gave the book to me, not you.

So in your sentence, mi is the normal natural choice.

Because Polish often expresses to someone through the dative case, not with a separate preposition.

In English:

• sent me
• sent to me

In Polish, mi already carries that function:

• wysłała mi

You do not need an extra word meaning to here.

Be careful not to confuse this with expressions that really do use a preposition, such as:

• do mnie = to me / toward me

That is a different structure.

Yes, it looks similar, but here grafik is a false friend for many English speakers.

In this sentence, grafik means:

• schedule
• rota
• shift schedule
• work timetable

In workplace Polish, grafik often refers specifically to a work schedule.

So:

• nowy grafik = a new schedule

It does not mean graphic in this sentence.

Because nowy agrees with grafik.

• grafik is masculine singular
• in this sentence it is the direct object
• because it is a masculine inanimate noun, its accusative form is the same as its nominative form

So:

• nominative: nowy grafik
• accusative: nowy grafik

That is why you see nowy, not another ending.

In Polish, na + accusative is often used for something intended for a future time period.

So:

• grafik na przyszły tydzień = a schedule for next week

This is a very common pattern.

Examples:

• plan na jutro = a plan for tomorrow
• bilet na piątek = a ticket for Friday
• grafik na przyszły tydzień = a schedule for next week

So na here does not mean literal movement onto something. It means for in the sense of meant for / covering that time.

Because after na in this meaning, Polish uses the accusative:

• na przyszły tydzień

But w przyszłym tygodniu is a different structure. It means:

• next week
• in the next week

So compare these carefully:

• grafik na przyszły tydzień = a schedule for next week
• w przyszłym tygodniu = next week, as a time when something happens

Example:

• Dostałem grafik na przyszły tydzień. = I got the schedule for next week.
• Dostałem go w przyszłym tygodniu. = I got it next week.

The first is about what the schedule covers. The second is about when something happens.

No, Polish word order is fairly flexible, but this sentence has a very natural, neutral order:

• Moja przełożona wysłała mi nowy grafik na przyszły tydzień.

Because Polish marks grammatical roles with endings and cases, you can move things around for emphasis. For example:

• Nowy grafik na przyszły tydzień wysłała mi moja przełożona.
• Moja przełożona nowy grafik na przyszły tydzień wysłała mi.

These are possible, but they sound more marked or emphatic.

The original order is the best choice for a straightforward statement.

Yes. That is a very natural translation.

Depending on context, przełożona and grafik could be rendered as:

• My supervisor sent me a new schedule for next week.
• My manager sent me a new rota for next week.
• My boss sent me a new work schedule for next week.

So even if the exact English wording changes, the Polish sentence stays the same.

You would change the words that agree with the subject’s gender:

• Mój przełożony wysłał mi nowy grafik na przyszły tydzień.

Changes:

• moja → mój
• przełożona → przełożony
• wysłała → wysłał

The rest stays the same.