У моєму телефоні є нагадування і список справ на завтра.

Because after у meaning in, Ukrainian uses the locative case for location.

• мій → моєму
• телефон → телефоні

So:

• у моєму телефоні = in my phone

The adjective/pronoun and the noun have to match in case, number, and gender.

Both у and в can mean in. Ukrainian often chooses between them for euphony—basically, whichever sounds smoother.

So both of these are possible:

• У моєму телефоні
• В моєму телефоні

In this sentence, у sounds a bit smoother at the start.

Yes. Ukrainian commonly uses у телефоні where English often says on my phone.

So:

• У моєму телефоні є... = There is/are ... on my phone

Literal word-for-word translation can sound like in my phone, but the natural English meaning is often on my phone.

Here є means there is / there are.

So:

• У моєму телефоні є нагадування... = There is a reminder in my phone...

This is an existence word: it tells you that something is present or available.

Important: in Ukrainian, the present tense of to be is often omitted in sentences like He is a student, but є is still commonly used when the meaning is there is / there are or have:

• У мене є брат. = I have a brother.
• У моєму телефоні є нагадування. = There is a reminder in my phone.

Because Ukrainian has no articles.

So нагадування can mean:

• a reminder
• the reminder

And список справ can mean:

• a to-do list
• the to-do list

You figure that out from context. English requires an article, but Ukrainian does not.

Because after a noun like список (list), the next noun is usually put in the genitive case.

So:

• список = list
• справ = of tasks / of things to do

This structure is very common:

• чашка чаю = a cup of tea
• центр міста = the city center / the center of the city
• список справ = a list of tasks

So справ is the correct form here.

На завтра means for tomorrow.

So:

• список справ на завтра = a to-do list for tomorrow
• нагадування на завтра = a reminder for tomorrow

This is a very common Ukrainian pattern:

• на сьогодні = for today
• на завтра = for tomorrow
• на вечір = for the evening

It often expresses something planned, intended, or relevant for that time.

Here it is understood as singular: a reminder.

A tricky point: with many neuter nouns ending in -ння, the nominative singular and nominative plural look the same in form.

So нагадування can mean:

• a reminder
• reminders

Context tells you which one is meant.

In this sentence, because it is paired with список (list, singular), the natural reading is:

• a reminder and a to-do list

Often yes.

• і = and
• й = a euphonic variant of і
• та = also means and in many contexts

So these can all be possible depending on sound and style:

• нагадування і список справ
• нагадування й список справ
• нагадування та список справ

In this sentence, і is the most neutral and straightforward choice.

No, Ukrainian word order is fairly flexible. But this order is very natural:

• У моєму телефоні є нагадування і список справ на завтра.

It starts with the location (in my phone) and then says what exists there.

You could rearrange parts, but the emphasis would change. For example:

• Є нагадування і список справ на завтра у моєму телефоні.

This is grammatical, but less neutral. The original sentence sounds more natural for everyday speech.