sohu ha, hourensou to kinoko no tenpura wo okawarisimasita.

は marks 祖父 as the topic of the sentence. It tells you, as for my grandfather... and then the rest of the sentence says something about him.

So the structure is:

• 祖父は = as for my grandfather
• ほうれん草ときのこの天ぷらを = spinach-and-mushroom tempura
• おかわりしました = had another helping

A learner often compares は and が here:

• は presents the topic
• が would put more focus on who did it

In this sentence, は is the natural choice because the sentence is simply talking about what the grandfather did.

祖父 is the usual word for my grandfather / our grandfather when speaking to someone else.

Japanese often uses different words depending on whether you are talking about:

• your own family to outsiders
• someone else’s family
• a family member directly

So:

• 祖父 = my grandfather / our grandfather
• おじいさん = grandpa, an elderly man, or someone else’s grandfather in many contexts

Using 祖父 here sounds neutral and appropriate for talking about one’s own grandfather.

Here, と means and.

So:

• ほうれん草ときのこ = spinach and mushrooms

This と is the basic noun-connecting and. It is used to list nouns.

Here, の links the ingredient phrase to 天ぷら.

So the phrase means:

• ほうれん草ときのこの天ぷら = tempura of spinach and mushrooms
• more naturally in English: spinach and mushroom tempura

A useful pattern is:

• AのB = B of A / B made from A / B related to A

Examples:

• えびの天ぷら = shrimp tempura
• 野菜の天ぷら = vegetable tempura

In this sentence, the whole ingredient group ほうれん草ときのこ is connected to 天ぷら.

を marks the direct object of the action.

The thing being acted on is:

• ほうれん草ときのこの天ぷら

So を shows that this is what the grandfather had another helping of.

Even though おかわりしました is not exactly the same as a simple verb like ate, it still works with を to mark the food item that got the second helping treatment.

おかわりしました is the polite past form of おかわりする.

Breakdown:

• おかわり = another helping, seconds, refill
• する = to do
• しました = did, in polite past form

So おかわりしました literally works like did a second helping, but in natural English it means:

• had another helping
• had seconds
• got a refill, depending on context

This is a very common expression with food and drink.

The お here is a polite prefix. It is part of the normal expression おかわり.

It does not mean the speaker is being especially respectful toward the food. It just makes the word sound natural and polite, which is common in everyday Japanese.

You should learn おかわり as a set expression.

It does both.

• する = non-past plain form
• した = past plain form
• します = non-past polite form
• しました = past polite form

So おかわりしました tells you:

• the action happened in the past
• the sentence is in polite style

A casual version would be:

• 祖父は、ほうれん草ときのこの天ぷらをおかわりした。

Japanese nouns usually do not change form for singular vs. plural.

So:

• きのこ can mean mushroom or mushrooms
• ほうれん草 can refer to spinach in a general ingredient sense

The exact number is understood from context.

This is normal in Japanese. The language also does not use articles like a or the, so learners often have to stop expecting those kinds of markers.

The sentence follows a very common Japanese pattern:

• Topic + object + verb

So:

• 祖父は = topic
• ほうれん草ときのこの天ぷらを = object
• おかわりしました = verb

Japanese verbs usually come at the end of the sentence, which is one of the biggest differences from English.

Not usually.

In normal Japanese writing, this would typically be written as:

• 祖父は、ほうれん草ときのこの天ぷらをおかわりしました。

Japanese normally does not use spaces between words. The comma after は is possible and can make the sentence a little easier to read, but it is not required.

In learning materials, spaces are often added to help beginners see the parts of the sentence.

Yes, if the grandfather is already understood from context.

Japanese often leaves out information that is obvious from the situation. So if everyone already knows you are talking about your grandfather, you could simply say:

• ほうれん草ときのこの天ぷらをおかわりしました。

The sentence would still be natural in the right context. Japanese drops subjects and topics much more freely than English does.