Learn Hardcore Japanese: watasi no ie de ha tiisai inu wo petto to site katte ite, mainiti issyo ni sanposimasu. - At my house we keep a small dog as a pet and take a walk together every day.

私の家で – grammatically fine, but it just says at my house without making it the topic/contrast.
私の家は – means my house is / as for my house but loses the clear “location of an action” nuance that で gives.

So 家では focuses on “in the context of my home (as opposed to other places).”

Why is 犬 marked with を (小さい犬をペットとして飼っていて) instead of が?

The verb 飼う (to keep/raise an animal) takes a direct object, so it uses を:

犬を飼う = to keep/raise a dog

が marks the subject of verbs like exist, like, want, etc., but 飼う is more like to have/keep (an animal) and treats the animal as the direct object.

So:

小さい犬を飼う = to keep a small dog (correct)
小さい犬が飼う – ungrammatical; it would literally mean “the small dog keeps (something)”

What does として in ペットとして mean?

として means “as” / “in the capacity of” / “in the role of.”

In this sentence:

小さい犬をペットとして飼っていて
= we keep a small dog as a pet
(not as a guard dog, not as livestock, etc.)

More examples:

先生として働く – work as a teacher
友達として話す – talk to (someone) as a friend

So として marks the “role” or “status” in which something is being treated.

What exactly is being modified by ペットとして? The dog, or the verb 飼う?

Grammatically, ペットとして is attached to 飼っていて (from 飼う):

犬を [ペットとして飼っていて]
= [keep the dog as a pet]

Semantically, this whole chunk tells you what kind of dog it is in that context: a dog that is kept in the role of a pet. So:

It’s not just “a small dog”
It’s “a small dog that we keep as a pet”

Why is it 飼っていて instead of 飼っています?

There are two things going on:

飼っている = “to be keeping / to have (an animal)” (continuous state)
- Plain: 飼っている
- Polite: 飼っています
Then that いる is put into -て form to connect to the next clause:
- 飼っていて、毎日一緒に散歩します。

So you can think of it as:

飼っている + て → 飼っていて
“(We) are keeping a small dog as a pet, and (we) walk together every day.”

If you used 飼っています there, you’d be ending the sentence:

ペットとして飼っています。毎日一緒に散歩します。
= Two separate sentences, also correct but a bit choppier.

飼っていて、 smoothly links the ongoing situation (we have a dog) to the next action (we walk).

Why is 散歩します used instead of 散歩に行きます?

Both are natural, but there’s a nuance:

散歩します
Literally “(we) do a walk” → take a walk / go for a walk
Very common and straightforward.
散歩に行きます
Literally “(we) go to a walk” → go (somewhere) for a walk
Slightly more focus on the going aspect.

In daily conversation, people often just say 散歩します or 散歩に行きます almost interchangeably. Here, 散歩します is concise and perfectly natural.

What is the role of に in 一緒に (毎日一緒に散歩します)?

一緒に is an adverbial expression meaning “together”:

一緒 = together
に turns it into an adverb modifying the verb:
- 一緒に散歩します = walk together

You can think of it like English together or togetherly modifying the verb walk.

So 一緒に answers “How do we walk?” → “We walk together.”

Why is 私 not repeated before 散歩します? How do we know who is walking?

Japanese often omits the subject if it’s clear from context.

The first part 私の家では…飼っていて gives the context “at my house, we keep a small dog as a pet”. In that context, it’s natural to understand that I (or my family and I) are the ones walking the dog.

Repeating 私 is usually unnecessary and can sound stiff:

(Natural)
私の家では小さい犬をペットとして飼っていて、毎日一緒に散歩します。
(Over-explicit)
私の家では小さい犬をペットとして飼っていて、私は毎日一緒に散歩します。

The second is not wrong, but the first is more typical Japanese.

What’s the difference between 家 and うち here? Could I say 私のうちでは instead?

Yes, you can say:

私のうちでは小さい犬をペットとして飼っていて…

Nuance:

家 (いえ)
More “house” as a building or home; slightly more neutral/formal.
うち
Very common in speech for “my home / my family / my household.”
It feels a bit warmer and more casual.

In many everyday contexts, 家 and うち overlap, and both are fine. Here:

私の家では – neutral
私のうちでは – a bit more homely/casual

Why is 小さい used before 犬? Could I use 小さな犬 instead, and is there a difference?

Both are correct:

小さい犬
小さな犬

小さい is an い-adjective, used in front of nouns as-is:

小さい犬 – small dog

小さな is a 連体詞 (rentaishi)-like form derived from the adjective, used only to modify nouns:

小さな犬 – also “small dog”, sometimes with a slightly more descriptive or literary feel.

In everyday speech, 小さい犬 is more common and neutral. 小さな犬 can sound a bit more expressive or story-like, but the difference is subtle.

Why is ペット written in katakana?

ペット is a loanword from English (“pet”), and in Japanese:

Loanwords from Western languages are normally written in katakana.

So:

ペット (katakana) is standard.
Writing it in hiragana or kanji would look very strange or playful.

What level of politeness is this sentence? Is it casual or polite?

The sentence ends with 散歩します, which is the polite ます-form, so the whole sentence is in polite style:

飼っていて、毎日一緒に散歩します。

Even though 飼っていて looks like a plain-form piece, it’s a clause connector leading into 散歩します. In Japanese, the level of politeness is judged mainly by the final verb form of the sentence, so this counts as polite.

You could make it casual by changing the last verb:

私の家では小さい犬をペットとして飼っていて、毎日一緒に散歩する。 (casual)
…散歩します。 (polite)