Я знайшов другий чобіт під столом.

A word-by-word breakdown:

• Я = I
• знайшов = found
  
  • past tense
  • masculine form, so it suggests the speaker is male
• другий = second / sometimes the other
• чобіт = boot
• під = under
• столом = table in the case required after під when talking about location

So the structure is basically:

I found + the second/other boot + under the table.

In the past tense, Ukrainian verbs agree with the gender and number of the subject.

For знайти (to find), the past forms are:

• знайшов = masculine singular
• знайшла = feminine singular
• знайшло = neuter singular
• знайшли = plural

So:

• Я знайшов = I found if the speaker is male
• Я знайшла = I found if the speaker is female

English does not show this gender difference in the verb, but Ukrainian does.

Yes. Ukrainian often drops subject pronouns when they are clear from context.

So both are possible:

• Я знайшов другий чобіт під столом.
• Знайшов другий чобіт під столом.

The full version with Я may sound a bit more explicit or emphatic, depending on context. English usually needs I, but Ukrainian often does not.

Literally, другий is the ordinal second.

But in real usage, другий чобіт can often mean:

• the second boot
• the other boot

This makes sense because boots usually come in pairs. So if one boot has already been mentioned or found, другий чобіт can naturally mean the other one.

Important point:

• другий is an adjective, so it changes to match the noun in gender, number, and case.

Here it is masculine singular nominative/accusative to match чобіт.

Because чобіт here is the direct object, and it is masculine singular inanimate.

In Ukrainian, masculine inanimate nouns usually have:

• nominative singular = чобіт
• accusative singular = also чобіт

Since знайшов takes a direct object, the noun is in the accusative case. But for masculine inanimate nouns, the accusative looks the same as the nominative.

So:

• nominative: чобіт
• accusative: чобіт

That is why you do not see чобота here.

Because під can take different cases depending on meaning.

• під + instrumental = location, under
• під + accusative = movement to a position under something, to under

Here the meaning is location: the boot was found under the table, not moved there in the sentence.

So:

• під столом = under the table (location)
• під стіл = to under the table / underneath the table (movement)

Compare:

• Чобіт був під столом. = The boot was under the table.
• Я поклав чобіт під стіл. = I put the boot under the table.

Because after під in a location meaning, Ukrainian uses the instrumental case.

The noun стіл (table) changes in the instrumental singular:

• стіл → столом

This is a normal case change. Many masculine nouns take -ом in the instrumental singular.

Examples:

• під столом = under the table
• за столом = at the table / behind the table
• перед будинком = in front of the house

So столом is simply the instrumental form of стіл.

Because adjectives in Ukrainian must agree with the noun they describe.

The noun чобіт is:

• masculine
• singular
• inanimate
• accusative here, but for masculine inanimate nouns the accusative looks like the nominative

So the adjective also appears in the matching form:

• другий чобіт

If the noun changed, the adjective would change too. For example:

• друга книжка = second book
• друге вікно = second window
• другі чоботи = second boots / the other boots

Agreement is a major feature of Ukrainian grammar.

The word order is fairly flexible, though different orders change the emphasis.

The neutral version is:

• Я знайшов другий чобіт під столом.

Other possible orders:

• Під столом я знайшов другий чобіт.
  Emphasizes under the table
• Другий чобіт я знайшов під столом.
  Emphasizes the second/other boot
• Я під столом знайшов другий чобіт.
  Also possible, with slightly different rhythm/focus

Because Ukrainian uses cases, word order often serves emphasis more than basic grammar.

Ukrainian has no articles like a or the.

So чобіт by itself does not tell you whether English should use a or the. That comes from context.

Depending on the situation, другий чобіт could be translated as:

• a second boot
• the second boot
• the other boot

In this sentence, English often prefers the other boot or the second boot, because the context strongly suggests a pair.

Only the past-tense verb would need to change:

• Я знайшла другий чобіт під столом.

Everything else stays the same.

So:

• male speaker: Я знайшов...
• female speaker: Я знайшла...

This is one of the first things English speakers notice about Ukrainian past tense.

A simple approximate pronunciation is:

Ya znayshóv druhýy chobít pid stolóm

A few notes:

• Я sounds like ya
• знайшов has stress on the last syllable: знайшÓв
• другий is pronounced roughly dru-HYY, with the stress on the second syllable
• чобіт has stress on the first syllable: CHO-bit
• під is roughly pid
• столом has stress on the last syllable: stolÓM

Exact pronunciation depends on accent and phonetic detail, but this gives a good starting point.

Because the sentence is talking about one boot: the second/other boot.

Ukrainian does not have a special grammatical dual form in modern standard usage. So if you talk about both boots, you would just use the plural:

• чоботи = boots

Examples:

• Я знайшов чоботи. = I found the boots.
• Я знайшов другий чобіт. = I found the other boot.

So Ukrainian simply uses singular for one item and plural for more than one.