sohu ha, sasimi yori tenpura no hou ga tabeyasui to itte ita.

より marks the thing being compared against. In this sentence, 刺身より means than sashimi.

So the pattern is:

• A より B のほうが ...
• B is more ... than A

Here:

• 刺身より = than sashimi
• 天ぷらのほうが = tempura, rather / tempura is the one that...
• 食べやすい = easy to eat

So より does not mean from here. It is the comparison particle than.

ほう literally means side or direction, but in comparisons it means something like the one / the option / the side.

So:

• 天ぷらのほうが = tempura is the one that... / as for tempura, it is more...

This pattern is extremely common in Japanese comparisons:

• A より B のほうが adjective
• B is more adjective than A

Examples:

• 犬より猫のほうが好きです。
  I like cats more than dogs.

• 電車よりバスのほうが安いです。
  Buses are cheaper than trains.

In your sentence, 天ぷらのほうが emphasizes that, of the two foods, tempura is the easier one to eat.

In the quoted clause, 天ぷらのほうが食べやすい, が marks the grammatical subject of 食べやすい.

So the inner sentence is structured like:

• 天ぷらのほうが = tempura is the thing that...
• 食べやすい = is easy to eat

Using が is very natural in comparison patterns like this. It helps focus on which one has the property.

You could sometimes see は in similar sentences, but が is the most standard choice in:

• A より B のほうが ...

So this sentence sounds natural and textbook-standard as written.

食べやすい is made from:

• 食べる = to eat
• verb stem 食べ-
• やすい = easy to do

So:

• 食べやすい = easy to eat

This is a very common grammar pattern:

• verb stem + やすい = easy to do
• verb stem + にくい = hard to do

Examples:

• 読みやすい = easy to read
• 分かりやすい = easy to understand
• 使いやすい = easy to use
• 食べにくい = hard to eat

So the sentence is talking about ease of eating, not necessarily preference or taste.

It means easy to eat, not tastes better.

That could refer to things like:

• texture
• shape
• how easy it is to pick up
• how comfortable it feels to eat
• how suitable it is for someone elderly

So the sentence does not directly say that the grandfather likes tempura more, or that tempura tastes better. It specifically comments on ease of eating.

と marks the content of what was said or thought.

So:

• 刺身より天ぷらのほうが食べやすい = the quoted content
• と = quotation marker
• 言っていた = was saying / said

This is the standard way to quote statements in Japanese:

• 「...」と言う
• ... と言う

You do not need quotation marks in Japanese for this structure, though they can be added in writing.

言っていた is the past form of 言っている, and it often has a softer, more contextual nuance than 言った.

Very roughly:

• 言った = said
• 言っていた = was saying / had said

In real Japanese, 言っていた can suggest things like:

• the speaker is recalling what the grandfather used to say
• the statement was made at some earlier point and is being reported now
• the saying may have been part of an ongoing conversation or repeated habit

So this sentence can feel a little more like Grandpa was saying that... or Grandpa had said that..., rather than a simple one-time said.

は marks 祖父 as the topic of the whole sentence.

So the overall structure is:

• 祖父は = as for my grandfather / my grandfather
• ...と言っていた = was saying that ...

This sets up grandfather as the person being talked about, and then the rest tells you what he said.

It is common in Japanese to mark the speaker/topic with は at the start, even when that person is not the grammatical subject of the quoted sentence inside.

By itself, 祖父 just means grandfather.

In many contexts, especially when speaking about your own family to other people, 祖父 is used for my grandfather. That is probably the intended meaning here.

A useful cultural note:

• 祖父 is a more neutral/formal term
• おじいさん can mean grandfather, but it can also mean old man or be used more generally

So in a sentence like this, 祖父 is a normal way to refer to one’s own grandfather.

Yes, Japanese word order is flexible, as long as the particles stay clear.

For example, these are close in meaning:

• 祖父は、刺身より天ぷらのほうが食べやすいと言っていた。
• 祖父は、天ぷらのほうが刺身より食べやすいと言っていた。

The first one is a very natural comparison pattern because A より B のほうが... is such a common set phrase.

So while some reordering is possible, the original order sounds very standard and smooth.

No, they are not grammatically necessary.

Japanese commas often reflect:

• rhythm
• readability
• emphasis
• the writer’s style

So:

• 祖父は刺身より天ぷらのほうが食べやすいと言っていた。

is also perfectly fine.

The commas in your sentence just make it a little easier to read by separating the topic and the comparison phrase.

Not naturally, if you want the same comparison structure.

For example, 刺身より天ぷらが食べやすい may be understandable, but A より B のほうが... is the much more natural and standard way to compare two things in Japanese.

So のほう is doing important work here: it clearly marks tempura as the compared choice.

That is why learners should treat this as a set pattern:

• A より B のほうが adjective

rather than trying to remove のほう.