Learn Hardcore Ukrainian: Ти міг би допомогти мені ввечері?

Ukrainian forms polite requests with the conditional: past tense + the particle би/б. So міг би means “could” rather than literal past time. It’s a standard way to soften a request: Ти міг би…? = “Could you…?”

Does міг imply the person I’m speaking to is male?

Yes. Past tense agrees with the subject’s gender:

to a man: Ти міг би допомогти…?
to a woman: Ти могла б допомогти…?
to polite singular or plural ви: Ви могли б допомогти…?

In letters/messages, capital Ви can show politeness: Ви могли б…?

Could I just say Ти можеш допомогти мені ввечері? What’s the difference?

Yes, it’s correct. Nuance:

Ти можеш…? / Чи можеш…? = “Can you…?” More direct/neutral.
Ти міг би…? = “Could you…?” Softer, more polite.
Even more polite: Чи не могли б ви…?

Why is it мені, not мене?

Because допомогти (“to help”) takes the dative case: допомогти кому? — “help to whom?” So: мені, тобі, йому, їй. If you add what to help with, use з/із or у/в:

допомогти мені з домашнім завданням
допомогти мені у приготуванні

Why допомогти and not допомагати?

допомогти (perfective) = a single, complete act: “help (once) this evening.”
допомагати (imperfective) = ongoing/habitual: “to be helping / help regularly.” For a one-off request, perfective допомогти is natural.

Is ввечері correct? What about увечері or вечором?

All are acceptable, with nuances of style/euphony.

ввечері and увечері are both standard adverbs meaning “in the evening.” Choose у/в by euphony (to avoid awkward sound clusters).
вечором (instrumental used adverbially) is common and a bit more colloquial/regional. Avoid Russian вечером in Ukrainian.

Is ввечері one word or two?

One word. It’s an adverb, like вранці/увранці (“in the morning”), вдень (“in the daytime”), вночі/уночі (“at night”). Don’t write в вечері as two words here.

Where does the particle би/б go? Can I say Ти б міг… or Міг би ти…?

Yes. би/б is a clitic that tends to appear after the first stressed element. All of these are fine:

Ти міг би допомогти…
Ти б міг допомогти…
Міг би ти допомогти… Form choice: after a consonant use би (e.g., міг би), after a vowel use б (e.g., ти б).

Do I need Чи to make it a question?

No. Yes/no questions can be marked by intonation alone: Ти міг би допомогти мені ввечері? Adding Чи is also correct and a bit more formal/explicit: Чи ти міг би…? You can also invert: Міг би ти…?

Can I drop the pronoun ти?

Yes, especially in casual speech: Міг би допомогти мені ввечері? Note that the verb still shows gender: Міг би… (to a man), Могла б… (to a woman).

How do I make it extra polite?

Add будь ласка: Ти міг би допомогти мені ввечері, будь ласка?
Use polite ви and a negative softener: Чи не могли б ви допомогти мені ввечері, будь ласка?

How is it pronounced and where is the stress?

міг: [mʲiɦ] (Ukrainian г is a voiced [ɦ], not [g])
би/б: unstressed clitic
допомогти́: stress on the last syllable
мені́: stress on -ні
вве́чері: stress on the first syllable; the double вв is pronounced as a single long-ish [ʋ] sound

Can I use зможеш or змогли б instead of можеш/міг би?

Yes, with a nuance:

Чи зможеш допомогти…? focuses on being able to manage at that specific time.
Чи можеш…? is more general ability/possibility.
Чи змогли б ви…? is also polite, similar to могли б, sometimes implying “manage to.”

How do I add what time in the evening or more detail?

Just expand the time expression:

…ввечері о сьомій? (at 7 p.m.)
…сьогодні ввечері / завтра ввечері?
Combine with what you need help with: …ввечері о сьомій з переїздом?