Szampon jest obok mydła przy umywalce.

Because obok requires the genitive case in Polish.

• Basic form: mydło = soap
• After obok = next to / beside, it changes to mydła

So:

• mydło = soap
• obok mydła = next to the soap

This is very common in Polish: certain prepositions force a specific case, and obok is one of the prepositions that takes the genitive.

Because przy takes the locative case.

• Basic form: umywalka = sink / washbasin
• After przy = by / near / at, it becomes umywalce

So:

• umywalka = sink
• przy umywalce = by the sink

This is another very common pattern in Polish:

• przy
  • locative

They are similar, but not identical.

• obok means next to / beside
• przy means by / near / at

In this sentence, they do different jobs:

• obok mydła = next to the soap
• przy umywalce = by the sink

So the full idea is: The shampoo is next to the soap, by the sink.

A helpful way to think about it:

• obok gives a more exact relationship: one thing is right beside another
• przy gives a broader location: something is near or at something else

Using both gives a more precise picture.

• obok mydła tells you where the shampoo is in relation to the soap
• przy umywalce tells you where this whole arrangement is located

So the sentence answers two location questions at once:

1. Where is the shampoo relative to the soap?
   Obok mydła.
2. Where is it all happening?
   Przy umywalce.

English does this too: The shampoo is next to the soap by the sink.

Szampon means shampoo.

It is a masculine inanimate noun in Polish. That is why the verb is:

• szampon jest = the shampoo is

It is singular, so jest is singular too.

Some useful forms:

• szampon = shampoo
• szampony = shampoos

Not always.

Umywalka usually means a washbasin / bathroom sink.
If you mean a kitchen sink, Polish often uses zlew.

So:

• umywalka = bathroom sink / washbasin
• zlew = kitchen sink

In this sentence, przy umywalce strongly suggests a bathroom or washroom setting.

In a normal full sentence like this, jest should be included.

• Szampon jest obok mydła przy umywalce. = normal, complete sentence

Polish sometimes drops forms of to be in certain styles or very informal notes, but with ordinary statements about location, jest is standard.

So for a learner, the safe rule is:

• when saying something is somewhere, use jest

Examples:

• Książka jest na stole. = The book is on the table.
• Ręcznik jest w łazience. = The towel is in the bathroom.

Yes. Polish word order is more flexible than English word order.

The original sentence:

• Szampon jest obok mydła przy umywalce.

is a natural, neutral order.

But you could also say:

• Obok mydła przy umywalce jest szampon.
• Przy umywalce szampon jest obok mydła.

These are grammatically possible, but they may shift the emphasis slightly.

For example:

• starting with Obok mydła... emphasizes the location
• starting with Szampon... feels more neutral and straightforward

So the original version is a very good default pattern for learners.

A rough English-friendly guide is:

SHAHM-pon yest OH-bok MID-wah pshee oo-mih-VAL-tseh

A few sound notes:

• sz sounds like sh
  • szampon → SHAHM-pon
• j in Polish sounds like English y
  • jest → yest
• ł sounds like English w
  • mydła → roughly MID-wah
• przy begins with a Polish prz cluster, which is hard for English speakers; pshee is only an approximation
• c in umywalce sounds like ts
  • -ce → tseh

Here it is singular.

That can be confusing because the ending -a may look plural to an English speaker, but in this case:

• dictionary form: mydło = soap
• genitive singular: mydła

So obok mydła means next to the soap, not next to the soaps.

Yes, very often you can.

• obok mydła = next to the soap
• koło mydła = by / beside / near the soap

Both are natural, though obok often feels a bit more clearly like right next to, while koło can sometimes be a little broader, more like near.

Both take the genitive case, so you still say:

• obok mydła
• koło mydła

A useful breakdown is:

• Szampon = shampoo
• jest = is
• obok mydła = next to the soap
• przy umywalce = by the sink

So the pattern is:

[thing] + [is] + [location phrase] + [additional location phrase]

This is a very common way to build simple descriptive sentences in Polish.

You can model other sentences on it:

• Kubek jest obok talerza na stole.
  The mug is next to the plate on the table.

• Ręcznik jest przy wannie.
  The towel is by the bathtub.

• Szczoteczka jest obok pasty przy lustrze.
  The toothbrush is next to the toothpaste by the mirror.