La infano ploris, kaj mia fratino konsolis ŝin.

La is the definite article, meaning the. So la infano means the child.

If you said just infano, it would mean a child or simply child depending on context. Esperanto has no separate word for a/an.

Because infano is normally gender-neutral. It just means child.

That is very common in Esperanto: many nouns do not automatically tell you the person’s sex. In this sentence, you only find out later that the child is female because of ŝin, which means her.

The ending -is marks the past tense in Esperanto.

So:

• ploras = cries / is crying
• ploris = cried / was crying
• konsolas = comforts / is comforting
• konsolis = comforted / was comforting

Esperanto uses the same past-tense ending for all subjects, so there is no change like I cried / she cried / they cried. It is always -is.

In Esperanto, the verb ending already carries the tense information. So ploris by itself means something like cried or was crying, depending on context.

Esperanto usually does not force the same distinction English does between she cried and she was crying. The context tells you how to understand it.

Kaj means and.

It connects the two parts of the sentence:

• La infano ploris
• mia fratino konsolis ŝin

So the full sentence means that both things happened in sequence or as part of the same situation.

Because mia means my, while mi means I.

So:

• mi = I
• mia = my

The ending -a is the adjective ending, and possessive words like mia, via, lia, ŝia behave like adjectives in Esperanto.

Because ŝin is the direct object form of ŝi.

• ŝi = she
• ŝin = her

The ending -n marks the direct object in Esperanto. In this sentence, mia fratino is the subject, and ŝin is the person being comforted.

So:

• mia fratino konsolis ŝin = my sister comforted her

From the context of the sentence. The first clause introduces la infano, and the second clause refers back to that person with ŝin.

Also, ŝin tells us the child is female. If the child were male, you would expect lin. If the speaker wanted to avoid specifying sex, they would usually rephrase the sentence instead of using ŝin.

Yes, Esperanto word order is fairly flexible because the grammar endings show each word’s role.

For example, Ŝin konsolis mia fratino would still mean My sister comforted her, because ŝin has the -n object ending.

However, La infano ploris, kaj mia fratino konsolis ŝin is the most neutral and natural order.

Because fratino is the subject of konsolis, not the object.

In Esperanto, the direct object gets -n, but the subject does not.

So here:

• mia fratino = the one doing the comforting
• ŝin = the one receiving the comforting

That is why only ŝin has -n.

Fratino means sister.

It is built from:

• frat- = sibling / brother-sister idea
• -in- = female suffix
• -o = noun ending

So fratino is literally a female sibling. Compare:

• frato = brother
• fratino = sister

This is a very common pattern in Esperanto.

Ŝ is pronounced like English sh.

So ŝin sounds roughly like sheen.

More broadly:

• ŝi sounds like shee
• ŝin sounds like sheen

The letter ŝ always has that sh sound in Esperanto.