Learn Hardcore Polish: Musimy przenieść spotkanie na jutro.

Przełożyć spotkanie na jutro. (most common)
Przesunąć spotkanie na jutro. (also fine)
Przenieść is widely used for moving things or moving a meeting’s location; for time it’s understandable, just a bit less precise than przełożyć.

Why is it na jutro and not do jutra?

na jutro = set/schedule something to take place tomorrow (target time).
do jutra = by/until tomorrow (deadline) or “see you tomorrow.”

Examples:

Przełóżmy spotkanie na jutro. = Let’s set it for tomorrow.
Zrób to do jutra. = Do it by tomorrow.

Can I drop the preposition and say “Musimy przenieść spotkanie jutro”?

No. Without na, jutro tells you when the action of moving happens (“We have to move it tomorrow”), not the new time of the meeting. To say “to tomorrow,” you need na jutro.

What case is spotkanie here, and why doesn’t it change form?

spotkanie is in the accusative singular, the direct object of przenieść. Neuter nouns have identical nominative and accusative forms, so it stays spotkanie.

Why is the perfective infinitive przenieść used after musimy?

Polish tends to use the perfective after verbs of necessity when you mean a single, complete action:

Musimy przenieść/przełożyć spotkanie na jutro. (one rescheduling to be done) Using the imperfective (przenosić/przekładać) would suggest repeated or ongoing action:
Musimy przenosić spotkania co tydzień. (we have to keep moving meetings every week)

How flexible is the word order?

Quite flexible. All of these are correct, with different emphasis:

Musimy przenieść spotkanie na jutro. (neutral)
Spotkanie musimy przenieść na jutro. (emphasis on “the meeting”)
Na jutro musimy przenieść spotkanie. (emphasis on “to tomorrow”) Poles often keep the “move X to Y” pieces close together for clarity: przenieść/przełożyć [spotkanie] na [jutro].

How can I make this softer or more polite?

Softer/conditional: Musielibyśmy przełożyć spotkanie na jutro.
As a question/request: Czy możemy przełożyć spotkanie na jutro?
Formal email: Uprzejmie proszę o przełożenie spotkania na jutro.

How do I say “Let’s move the meeting to tomorrow”?

Use the 1st person plural imperative:

Przełóżmy spotkanie na jutro. (most idiomatic for time)
Przenieśmy spotkanie na jutro. (also possible)

How do I specify a part of the day, like “tomorrow morning”?

Add a time-of-day expression after jutro:

na jutro rano (tomorrow morning)
na jutro po południu (tomorrow afternoon)
na jutro wieczorem (tomorrow evening) Avoid doubling the preposition: say na jutro rano, not “na jutro na rano.”

How do I pronounce the tricky bits?

Musimy [muˈɕimɨ] — stress the second-to-last syllable; “si” before a consonant = soft “sh” sound [ɕ].
przenieść [ˈpʂɛɲeɕt͡ɕ] — “rz” in prz- is de-voiced to [ʂ]; “ń” = [ɲ]; “ś/ć” are soft [ɕ]/[t͡ɕ].
spotkanie [spɔtˈkaɲɛ] — stress on “-ka-”; “ń” = [ɲ].
na [na]
jutro [ˈjutrɔ] — “u” like “oo” in “boot.” General rule: Polish stress is almost always on the penultimate syllable.

How do I say “We don’t have to move the meeting to tomorrow”?

Use the imperfective in negatives:

Nie musimy przenosić/przekładać spotkania na jutro. The imperfective sounds more natural when denying the necessity of an action.

How can I explicitly say “move today’s meeting to tomorrow”?

Musimy przenieść dzisiejsze spotkanie na jutro.
Or as a suggestion: Dzisiejsze spotkanie przenieśmy na jutro.

Does jutro decline?

No. jutro is (mostly) an indeclinable adverb, so it stays jutro after prepositions like na. That’s why it’s na jutro, never “na jutra.”

How do I say “the meeting” vs. “this meeting” in Polish?

Polish has no articles, so plain spotkanie can mean “the meeting.” To specify “this meeting,” use a demonstrative:

To spotkanie musimy przełożyć na jutro. (This meeting we need to move to tomorrow.)