sensei no hanasikata ha yasasikute, wakariyasui desu.

It means the teacher’s way of speaking.

• 先生 = teacher
• の = links nouns, often like ’s or of
• 話し方 = way of speaking

So 先生の話し方 is literally the teacher’s speaking method/style, or more naturally, the teacher’s way of speaking.

Here, の connects two nouns:

• 先生 → teacher
• 話し方 → way of speaking

So 先生の話し方 means the teacher’s way of speaking.

This is one of the most common uses of の: noun + の + noun.

Examples:

• 日本の文化 = Japanese culture
• 友だちの名前 = a friend’s name
• 先生の話し方 = the teacher’s way of speaking

話し方 means way of speaking or manner of speaking.

It is built from:

• 話し = the ます-stem of 話す (to speak)
• 方（かた） = way of doing something

This pattern is very common:

• 書き方 = way of writing / how to write
• 読み方 = way of reading / how to read
• 使い方 = way of using / how to use
• 話し方 = way of speaking / how someone speaks

So 話し方 is not just speech in general; it emphasizes how someone speaks.

は marks the topic of the sentence.

So in: 先生の話し方は優しくて、分かりやすいです。

the topic is 先生の話し方 = the teacher’s way of speaking.

Then the sentence says something about that topic:

• it is gentle
• and easy to understand

A natural way to think of it is:

As for the teacher’s way of speaking, it is gentle and easy to understand.

Because 優しい is an い-adjective, and the correct て-form of an い-adjective is made by changing the final い to くて.

So:

• 優しい → 優しくて
• 面白い → 面白くて
• 難しい → 難しくて

That is why 優しいて is incorrect.

It connects 優しい to the next description, 分かりやすいです.

So:

• 優しくて = gentle, and...
• 分かりやすいです = easy to understand

Together: 優しくて、分かりやすいです = is gentle and easy to understand

In this sentence, て is mainly being used to link adjectives.

Usually, no. In this sentence it is most naturally just connecting two qualities:

• gentle
• easy to understand

So the meaning is: The teacher’s way of speaking is gentle and easy to understand.

It is true that て-form can sometimes show reason or cause, but here the simple and meaning is the most natural interpretation.

Literally, it is something like easy to understand.

It is made from:

• 分かる = to understand
• やすい = easy to do

So:

• 分かりやすい = easy to understand
• 読みやすい = easy to read
• 使いやすい = easy to use
• 話しやすい = easy to talk with / easy to speak to

This verb stem + やすい pattern is very common in Japanese.

Because です comes at the end of the predicate.

In a chain like this:

• 優しくて = connected form, not sentence-final
• 分かりやすいです = final part of the sentence

Only the last item needs to carry the polite ending.

Compare:

• この本は面白くて、長いです。
• 彼は親切で、明るいです。

You do not say:

• 優しいですて、分かりやすいです ✘

Yes. It is polite because it ends with です.

Polite version:

• 先生の話し方は優しくて、分かりやすいです。

Plain version:

• 先生の話し方は優しくて、分かりやすい。

So this is a normal polite statement, suitable in everyday conversation and writing.

Yes, that can be said, but the nuance changes slightly.

• は marks the topic: As for the teacher’s way of speaking...
• が can sound more like identifying what has those qualities.

In many everyday situations, both can work. But は feels very natural here if you are simply talking about the teacher’s way of speaking as the topic.

So:

• 先生の話し方は... = talking about it as the topic
• 先生の話し方が... = can place more focus on that specific thing

Because 分かる / わかる is often written either way.

Both are common:

• 分かりやすい
• わかりやすい

In many textbooks, apps, or casual writing, hiragana is often used because it is easier to read. The meaning does not change.

Here it describes the way of speaking, so it means something like:

• gentle
• soft
• kind-sounding

It is not necessarily saying the teacher is kind as a person, although it may suggest that too. Grammatically, 優しい is directly describing 話し方.

So the focus is on how the teacher speaks.

Yes, that is a very natural English translation.

Even though the Japanese literally talks about the teacher’s way of speaking, natural English may use a verb:

• The teacher’s way of speaking is gentle and easy to understand.
• The teacher speaks gently and clearly.
• The teacher has a gentle, easy-to-understand way of speaking.

All of these capture the idea well.