wǒ gāngcái zài gōngyuán kàndào liǎng zhī gǒu.

Mandarin usually doesn’t use a separate word like “did/was” for past tense.

In 我刚才在公园看到两只狗:

• 刚才 (“just now / a moment ago”) is a time word that already tells you it happened in the past.
• The verb 看到 (“to see / to catch sight of”) can refer to a completed action, especially with a past-time word.

Mandarin often indicates time with:

• Time expressions: 昨天, 刚才, 上个星期…
• Aspect particles: 了, 过, 着 (when needed)

Because 刚才 is clear enough, you don’t have to add a 了 here. Many native speakers would also say:

• 我刚才在公园看到了两只狗。

Both are natural; the time word itself already marks it as past.

Both relate to “recently / just,” but they’re used a bit differently.

• 刚

  • Literally “just (now), just recently.”
  • Modifies the verb directly.
  • Often used like an adverb: 我刚看到两只狗。 (“I just saw two dogs.”)
  • Focuses on how recent the action is.

• 刚才

  • A time noun meaning “a moment ago / just now (in the past).”
  • Used more like “earlier, a short time ago,” not exactly this instant.
  • Can function as a time expression: 我刚才在公园。 (“I was at the park a moment ago.”)

In your sentence, 刚才 sets the time frame:

• 我刚才在公园看到两只狗。
  “I (a moment ago) at the park saw two dogs.”

If you swap to 刚, it’s still OK but a bit different in feel:

• 我刚在公园看到两只狗。
  Emphasis feels slightly more on the recency of the seeing action itself, rather than on “a moment ago” as a time point.

Yes, 在 has two very common uses:

1. Preposition for location (“at / in / on”)

   • Pattern: 在 + place + Verb
   • In your sentence:
     
     • 在公园 = “at the park”
     • 我刚才在公园看到两只狗。 = “I just now at the park saw two dogs.”

2. Progressive marker (“be doing”)

   • Pattern: 在 + Verb
   • Example: 我在看书。 = “I’m reading.”

In 我刚才在公园看到两只狗, 在 clearly belongs with 公园, so it’s the location preposition, not the progressive marker.

If it were progressive, you’d see something like:

• 我刚才在看书。 = “I was reading just now.”
  (No place after 在 here; it goes directly before the verb 看.)

The general Mandarin word order for this kind of sentence is:

[Subject] + [Time] + [Place] + [Verb] + [Object]

So:

• Subject: 我
• Time: 刚才
• Place: 在公园
• Verb: 看到
• Object: 两只狗

→ 我 + 刚才 + 在公园 + 看到 + 两只狗。

You can move 刚才 a bit:

• 刚才我在公园看到两只狗。 (Time at the very beginning)
• 我在公园刚才看到两只狗。 (much less natural; we normally don’t put 刚才 there)

But you cannot say 在刚才公园; 在 introduces place, not time. Time words like 刚才、昨天、晚上 stand on their own and usually come before the place phrase.

只 (zhī) is a measure word (classifier) used for many animals and some small things.

Structure:
Number + Measure Word + Noun

So:

• 两 (two) = number
• 只 = measure word
• 狗 = noun

→ 两只狗 = “two dogs”

You must have a measure word when counting nouns in Mandarin; you can’t say:

• ✗ 两狗
• ✗ 两狗只

For animals, 只 is the most common classifier. There are other classifiers for some animals (e.g. 条 for long, thin ones), but 只 is the basic, default one for “dog.”

The standard, neutral classifier for “dog” is 只:

• 一只狗，两只狗

However, in certain contexts you might see:

• 条狗: using 条, which is normally for long, flexible things (条鱼, 一条河).
  
  • With 狗, 条 can sound colloquial or slightly pejorative / casual, depending on tone and context.
  • It’s not the “textbook safe” choice.

For learners, use 只 for dogs almost all the time. It’s the most natural and broadly correct option.

Mandarin has two common words for “two”:

• 二 (èr) – used in:

  • Numbers, counting: 一、二、三…
  • Phone numbers, addresses, math, etc.
  • Ordinals with 第: 第二 (“second”)

• 两 (liǎng) – used before measure words and some nouns:

  • 两只狗 (two dogs)
  • 两个人 (two people)
  • 两本书 (two books)

So in your sentence, because “two” comes before a classifier (只), you must use 两:

• ✔ 两只狗
• ✗ 二只狗 (this sounds wrong in everyday Mandarin)

All involve seeing/looking, but they differ in detail:

1. 看 (kàn) – “to look / to watch / to read”

   • Focuses on the action of looking, not necessarily successfully seeing something.
   • Example: 我在看电视。 – “I am watching TV.”

2. 看到 (kàndào) – “to see / to catch sight of”

   • A resultative verb compound: 看 (look) + 到 (arrive/achieve).
   • Implies you successfully saw it.
   • In your sentence: 看到两只狗 = “(managed to) see two dogs.”

3. 看见 (kànjiàn) – also “to see / catch sight of”

   • Very close in meaning to 看到; often interchangeable.
   • Some speakers feel 看见 is slightly more colloquial, but the difference is small.

In many contexts, 看到 ≈ 看见:

• 我在公园看到两只狗。
• 我在公园看见两只狗。

Both are fine and both mean “I saw two dogs at the park.”

Both are possible:

• 我刚才在公园看到两只狗。
• 我刚才在公园看到了两只狗。

看到了 = 看 (look) + 到 (achieve) + 了 (perfective aspect)

• Adding 了 often emphasizes that the action is completed or that the speaker is presenting a new fact.
• Without 了, the sentence is still past because of 刚才, but it can feel a bit more neutral or narrative.

In everyday speech, both versions are common. With clear past-time words like 刚才, 昨天, etc., native speakers often omit 了 when the past-ness is already obvious.

As a learner, it’s safe to use 看到了 to clearly mark a completed action:

• 我刚才在公园看到了两只狗。

Mandarin usually does not change the noun form to show plural. Plural is expressed by:

• Numbers + measure word: 两只狗, 三本书, 五个人
• Context: 我喜欢狗。 can mean “I like dog(s).”

The suffix 们 is:

• Mostly for people/pronouns: 我们, 你们, 他们, 孩子们
• Very rarely used with animals; if used, it tends to sound personifying or poetic.

So:

• 两只狗 already clearly means two dogs — no need for 狗们.
• 狗们 is unusual and would suggest “the dogs (as a group, personified),” not just “some dogs.”

You can move 在公园, but the meaning focus shifts:

1. 我刚才在公园看到两只狗。

   • Neutral, standard: “I (just now at the park) saw two dogs.”
   • Emphasis: where you were.

2. 我刚才看到两只狗在公园。

   • Sounds more like: “I (just now) saw two dogs that were in the park.”
   • Emphasis: where the dogs were.

In #2, 在公园 feels like it modifies 两只狗 (“two dogs [that are] at the park”), not your location. It’s not wrong, but it has a slightly different nuance. The original sentence is the most straightforward way to say “I was at the park and I saw two dogs.”

刚才 is a time expression, and time expressions are somewhat flexible. Common positions:

1. After the subject:

   • 我刚才在公园看到两只狗。
     Very natural.

2. At the very beginning:

   • 刚才我在公园看到两只狗。
     Also natural; puts a bit more emphasis on the time frame “a moment ago.”

Less natural:

• 我在公园刚才看到两只狗。 (unusual)
• 我在刚才公园看到两只狗。 (wrong; 刚才 is not a place)

So the best positions: [刚才] goes either right after the subject or at the very start of the sentence.

Good observation: there are two different characters/words:

1. 只 (zhī, first tone) – measure word for animals, some small items, etc.

   • Example: 一只狗，两只鸟，一只鞋

2. 只 (zhǐ, third tone) – adverb meaning “only / just / merely”

   • Example: 我只有一只狗。 – “I only have one dog.”

In your sentence:

• 两只狗 uses 只 (zhī), the measure word.
• Pronunciation: zhī, high-level first tone, not third tone.

So it’s important to distinguish by tone and function in the sentence.