Learn Hardcore Indonesian: Teman saya dan saya saling bertanya selama lima menit sebelum rapat. - My friend and I ask each other questions for five minutes before the meeting.

Both are grammatical. Many speakers find Saya dan teman saya a bit smoother, but Teman saya dan saya is fine too. In everyday speech, people often avoid repeating saya by just saying Kami (we, exclusive).

Can I replace "Teman saya dan saya" with "Kami" or "Kita"? What’s the difference?

Yes. Use:

Kami = we (excluding the person you’re talking to). Best here: Kami saling bertanya...
Kita = we (including the person you’re talking to). Only use if the listener was part of the “we.”

What does "saling" mean, and do I need it here?

Saling means “each other/mutually” and marks a reciprocal action. With two or more subjects, saling bertanya means “ask each other.” Without saling, bertanya just means “to ask (a question),” not necessarily to each other.

Can I say both "saling" and "satu sama lain" together?

It’s redundant in standard Indonesian. Say either saling bertanya or bertanya satu sama lain, not both together. Colloquially you might hear both, but it’s better style to choose one.

Is "saling bertanya" the same as "bertanya-tanya"?

No. Bertanya-tanya means “to wonder” (asking yourself), not “to ask each other.” For example:

Kami saling bertanya. = We asked each other.
Saya bertanya-tanya kapan rapat dimulai. = I wonder when the meeting starts.

How are "bertanya," "menanyakan," and "tanya" different?

Bertanya = to ask (intransitive). Often followed by a person with kepada or a topic with tentang/soal. Example: Saya bertanya kepada guru.
Menanyakan = to ask about (transitive, needs an object). Example: Saya menanyakan jadwal kepada guru.
Tanya = the root; colloquial/short form. Example: Saya tanya guru. (informal) Avoid tautologies like menanyakan pertanyaan; say menanyakan sesuatu/hal instead.

If I want to say “ask someone,” which preposition should I use?

Use kepada (or pada in formal writing) for the person: Saya bertanya kepada teman saya. With menanyakan, use kepada for the person and put the topic as the object: Saya menanyakan agenda kepada bos. With saling, you typically don’t need kepada.

Why "selama" for “for five minutes”? Can I use "untuk" or "dalam"?

Selama marks duration: selama lima menit = for five minutes.
Untuk expresses purpose; not used for bare duration in this sense (except in set phrases like untuk lima menit ke depan = for the next five minutes).
Dalam lima menit means “within/in five minutes” (time limit or countdown), not a duration you spent doing something.

What’s the difference between "Selama lima menit sebelum rapat, ..." and "Lima menit sebelum rapat, ..."?

Selama lima menit sebelum rapat, ... = for a five-minute span leading up to the meeting.
Lima menit sebelum rapat, ... = at the point in time five minutes before the meeting (a time marker), not necessarily for a five-minute duration.

Does this sentence indicate past or future time? Indonesian doesn’t mark tense, right?

Correct—Indonesian doesn’t mark tense on the verb. Time comes from context or time words. To be explicit, add:

Past: tadi, kemarin (e.g., Tadi kami saling bertanya...)
Future: akan, nanti (e.g., Nanti kami akan saling bertanya...)

Is "sebelum rapat" enough, or should I say "sebelum rapat dimulai"?

Both are fine. Sebelum rapat is concise and idiomatic. Sebelum rapat dimulai is more explicit. You can also say menjelang rapat (“as the meeting approached”) for a stylistic alternative.

Is "rapat" the best word here? What about "pertemuan" or "meeting"?

Rapat: a formal work/organizational meeting (most common in offices).
Pertemuan: any meeting/encounter; broader and often a bit more formal or general.
Meeting: English loan, common in business slang, but rapat is preferred in standard Indonesian.

Why isn’t "menit" pluralized? Should it be "menit-menit"?

Indonesian doesn’t mark plural with an ending like -s. A number already shows plurality: lima menit. Reduplication (menit-menit) is only used for special meanings (various minutes, minute-by-minute), not needed here.

Can I move the time phrases around?

Yes. All of these are natural, with slightly different emphasis:

Sebelum rapat, kami saling bertanya selama lima menit.
Selama lima menit sebelum rapat, kami saling bertanya.
Kami saling bertanya selama lima menit sebelum rapat. Fronting a time phrase is common to set the scene.

Is "dan" always used for “and”? Can I use "sama"?

Dan is the standard coordinator for “and.” Sama can mean “with” and is also used colloquially for “and”: Teman saya sama saya... (informal). In formal writing, stick with dan.

Could I make it more informal or more formal by changing pronouns?

Formal/neutral: saya; Teman saya dan saya... or better Kami...
Informal: aku and possessives like temanku → Aku dan temanku saling bertanya...
Very informal/Jakarta slang: gue/gua → Gue dan temen gue... (use with care; strongly colloquial)