kodomo ha zitto suwatte ita.

は marks 子供 as the topic of the sentence: as for the child / the children...

So the sentence is not just identifying who did the action; it is presenting 子供 as what the sentence is about.

• 子供は = the child / the children, as for them
• If it were 子供が, the nuance would be more like the child is the one who..., often with a more specific or contrastive focus.

In many simple contexts, both can be translated similarly in English, but は sounds more natural when you are just describing what was going on.

It can mean either child or children. Japanese nouns usually do not change form for singular vs. plural.

So:

• 子供 can mean a child
• 子供 can also mean children

You decide from context. If the broader context shows one child, translate it as the child. If it shows several, translate it as the children.

じっと is an adverb that means something like:

• still
• motionlessly
• quietly without moving
• sometimes intently, depending on context

In this sentence, with 座っていた, it means the child was sitting still.

So じっと adds the idea that the child was not fidgeting or moving around.

Because じっと is an adverb, and adverbs in Japanese often come before the verb or verb phrase they modify.

Here:

• じっと modifies 座っていた
• so it tells you how the child was sitting

A natural way to think of it is:

• じっと座っていた = was sitting still

This is very normal Japanese word order.

座っていた is 座る in the -ている form, put into the past:

• 座る = to sit
• 座っている = is sitting / is seated
• 座っていた = was sitting / was seated

In this sentence, it usually describes an ongoing state in the past.

So it is closer to:

• was sitting
• was seated

than to a simple one-time action like sat down.

Because 座った and 座っていた are different.

• 座った = sat down / sat
  • focuses more on the action happening
• 座っていた = was sitting / had been seated
  • focuses more on the ongoing state

So:

• 子供は座った。 = The child sat down.
• 子供は座っていた。 = The child was sitting.

Adding じっと makes it even clearer that the sentence is describing a continuing state: The child was sitting still.

The て is part of the -て form of the verb 座る.

• 座る becomes 座って
• then いる is added: 座っている
• in the past, いる becomes いた: 座っていた

This -ている pattern is extremely common in Japanese. It often expresses:

• an action in progress
• or a resulting state

With 座る, it usually describes the state of being seated.

いた is the plain form; いました is the polite form.

So:

• 座っていた = plain style
• 座っていました = polite style

The sentence in your example is in plain style, which is very common in:

• stories
• casual conversation
• written narration
• dictionary-style examples

The meaning is basically the same; the difference is style and level of politeness.

Yes, depending on context.

Most of the time, in a simple sentence like this, it will be understood as:

• was sitting
• was sitting still

But in the right context, it can also be translated as:

• had been sitting

For example, if another past event interrupted that state, English might prefer had been sitting.

So the exact English tense depends on the surrounding sentences, even though the Japanese form stays the same.

It is pronounced jitto.

Important point:

• the small っ means a brief pause or doubled consonant
• so it is not jito
• it is more like jit-to

That little pause is important for correct pronunciation.

Yes, that can be a natural English translation.

However, grammatically, 座っていた is closer to was sitting than to simple sat.

So these are all possible depending on context and style:

• The child was sitting still.
• The child sat still.
• The child remained seated quietly.

If you want to stay close to the Japanese grammar, was sitting still is often the safest choice.

The basic order is very normal:

• 子供は = topic
• じっと = adverb
• 座っていた = verb phrase

Japanese often puts descriptive elements before the verb, and the verb comes at the end.

So the sentence structure is straightforward and natural: As for the child, [he/she] was sitting still.

You could sometimes move adverbs around for nuance, but this order is the most standard and expected.