suzume ha tiisai.

It is read Suzume wa chiisai.

• 雀 = すずめ (suzume), meaning sparrow
• は is written ha but here it is pronounced wa
• 小さい = ちいさい (chiisai), meaning small

So the full reading is すずめは ちいさい.

When は is used as the topic particle, it is pronounced wa.

So in this sentence:

• 雀 = the topic
• は = topic marker, pronounced wa
• 小さい = small

This is one of the first pronunciation exceptions learners meet in Japanese. As a normal syllable inside a word, は is usually read ha, but as a particle it is often read wa.

は marks 雀 as the topic of the sentence.

A simple way to understand it is:

• As for sparrows, they are small
• or more naturally, Sparrows are small

The topic is what the sentence is talking about. Japanese often organizes sentences as:

topic + は + comment

Here:

• 雀は = as for sparrows
• 小さい = are small

Because 小さい can already function as the predicate by itself.

小さい is an i-adjective, and i-adjectives can end a sentence on their own in plain style:

• 雀は小さい。 = plain style
• 雀は小さいです。 = polite style

Both are correct. The version without です is not incomplete; it is just less polite and more plain/casual.

小さい is an i-adjective.

In Japanese, adjectives are often divided into two major groups:

• i-adjectives: end in -い
• na-adjectives: usually need な before a noun

Since 小さい ends in い, it is an i-adjective. That means it can directly describe a noun or end a sentence:

• 小さい雀 = a small sparrow
• 雀は小さい = sparrows are small

Both は and が can sometimes be translated similarly in English, but they do different jobs.

• は marks the topic
• が often marks the subject more directly and can add a sense of identification, emphasis, or new information

With 雀は小さい, the sentence sounds like a general statement about sparrows:

• As for sparrows, they are small

If you said 雀が小さい, it could sound more like:

• The sparrow is small
• or It is sparrows that are small, depending on context

For a basic general statement, は is very natural.

It can mean either, depending on context.

Japanese nouns usually do not change form for singular and plural. So 雀 can mean:

• a sparrow
• sparrows
• the sparrow
• sparrows in general

In a simple sentence like this, it is often understood as a general statement about sparrows as a kind of animal.

Yes, but Japanese word order is different from English.

This sentence follows a very common Japanese pattern:

topic + adjective/predicate

So:

• 雀は = topic
• 小さい = comment/predicate

In English, we say Sparrows are small.
In Japanese, the adjective often comes at the end of the sentence.

That means the sentence structure is not literally subject + verb + object here. Instead, it is more like:

As for sparrows — small.

Yes. 小さい雀 means small sparrow or a small sparrow.

The difference is:

• 雀は小さい。 = The sparrow / Sparrows are small.
  
  • complete sentence
• 小さい雀 = small sparrow
  
  • noun phrase, not a complete sentence by itself

So 小さい can either:

• describe a noun directly: 小さい雀
• act as the predicate: 雀は小さい

They are usually added only for learners.

Normal Japanese writing usually does not use spaces:

• 雀は小さい。

Textbooks or beginner materials sometimes insert spaces to make the parts easier to see:

• 雀　は　小さい。

So the spaces are not part of standard Japanese spelling.

It is plain style.

• 雀は小さい。 = plain
• 雀は小さいです。 = polite

Plain style is common in:

• casual conversation
• dictionary forms
• textbooks
• written explanations
• inner thoughts

It is not rude by itself, but it is less polite than the です form.