Kiedy niemowlę płacze, czasem pomaga smoczek, a czasem mała grzechotka.

Because Kiedy niemowlę płacze is a subordinate clause: when the baby cries.

In Polish, clauses introduced by words like kiedy (when), że (that), jeśli (if), and similar conjunctions are normally separated by a comma.

So:

• Kiedy niemowlę płacze, ...
• When the baby cries, ...

That comma is standard Polish punctuation.

Kiedy means when here.

It introduces a time clause:

• Kiedy niemowlę płacze = When a baby cries

Depending on context, kiedy can also mean whenever, not just one specific time. In this sentence, it has a general meaning:

• Whenever a baby cries, sometimes a pacifier helps, and sometimes a small rattle.

So it is not necessarily about one single baby crying once.

Niemowlę is a neuter noun meaning baby/infant.

A learner may expect a masculine or feminine noun for a person, but Polish has several nouns for young beings that are grammatically neuter, including forms ending in -ę.

In this sentence, niemowlę is in the nominative singular, because it is the subject of płacze:

• niemowlę płacze = the baby cries

Important point: grammatical gender in Polish does not always match natural gender.

Płacze is the 3rd person singular present tense of płakać (to cry).

It matches niemowlę, which is singular:

• niemowlę płacze = the baby cries

Some useful forms of płakać are:

• ja płaczę = I cry
• ty płaczesz = you cry
• on/ona/ono płacze = he/she/it cries

Because niemowlę is grammatically neuter, Polish would traditionally pair it with ono płacze, though in real life speakers often use natural-gender wording in other contexts.

Because the sentence contrasts two possibilities:

• czasem pomaga smoczek
• a czasem mała grzechotka

This means:

• sometimes a pacifier helps
• and sometimes a small rattle

Repeating czasem makes the contrast clear and natural. It is similar to English sometimes ..., and sometimes ...

Also, czasem is a common adverb meaning sometimes. You may also see czasami, which means the same thing in most contexts.

Both are possible.

• pomaga smoczek
• smoczek pomaga

Polish word order is more flexible than English word order. The version in your sentence puts the verb first in that part of the sentence and sounds natural in a general descriptive statement.

Very roughly:

• pomaga smoczek can feel a bit more like what helps is a pacifier
• smoczek pomaga is more neutral or straightforward: the pacifier helps

The actual meaning stays the same. The choice is about information flow and emphasis, not a basic grammar change.

Because they are the subjects of the verb pomaga.

In English, the structure is:

• a pacifier helps
• a small rattle helps

So in Polish:

• smoczek pomaga
• mała grzechotka pomaga

Even though English sometimes feels like helps the baby, the things doing the helping are the pacifier and the rattle, so they stay in the nominative.

Yes, pomagać often takes a dative object: to help someone/something.

For example:

• Pomagam mamie. = I help Mom.
• To pomaga dziecku. = This helps the child.

In your sentence, the person being helped is understood from context: it is the crying baby. Polish often leaves that unstated when it is obvious.

So the full idea is something like:

• Kiedy niemowlę płacze, czasem smoczek pomaga niemowlęciu, a czasem mała grzechotka.

Here niemowlęciu is the dative form of niemowlę.

But since it is clear from context, Polish naturally omits it.

Because each subject is singular:

• smoczek = singular
• mała grzechotka = singular

So:

• smoczek pomaga
• mała grzechotka pomaga

Even though there are two possible helpers mentioned in the whole sentence, they are presented separately, not as a combined plural subject.

If the sentence meant that both things help together, you would expect a plural verb:

• Smoczek i mała grzechotka pomagają. = The pacifier and the small rattle help.

But that is not the structure here.

In this sentence, a is a natural contrastive linker.

• czasem pomaga smoczek, a czasem mała grzechotka

Here a means something like:

• and on other occasions
• while at other times
• and sometimes instead

It is not exactly the same as i.

Very roughly:

• i = simple and
• a = and/but/while, often with contrast or comparison

Since the sentence is contrasting two different things that may help, a is the better choice.

Mała is the adjective small, and it agrees with grzechotka in gender, number, and case.

Because grzechotka is:

• feminine
• singular
• nominative

the adjective must also be:

• feminine
• singular
• nominative

So:

• mały = masculine form
• mała = feminine form
• małe = neuter form

That is why you get:

• mała grzechotka = a small rattle

Yes. That is a very close structural translation.

A few notes:

• niemowlę is often baby or infant
• smoczek is usually pacifier in American English or dummy in British English
• grzechotka is rattle
• czasem ... a czasem ... = sometimes ... and sometimes ...

So a literal-style translation is perfectly reasonable:

• When a baby cries, sometimes a pacifier helps, and sometimes a small rattle.

A more natural English rendering might also be:

• When a baby cries, sometimes a pacifier helps, and sometimes a little rattle does.

Yes, that would also be natural.

a innym razem means and other times or and at other times.

So:

• czasem ..., a czasem ...
• czasem ..., a innym razem ...

Both work. The version with czasem repeated is very simple and common. The version with innym razem adds a bit of variety and can sound slightly more stylistic.

The meaning is basically the same.