Learn Hardcore Japanese: kaigi ha muryou to itte mo, yoyaku ga hituyou desu. - Even though the meeting is free, a reservation is necessary.

It’s a fixed expression built from 言う (to say) + て-form + も, meaning “even though (it’s said/called) X; admittedly X, but ….” It downplays or qualifies the first statement and introduces a limit or exception in the second clause.

Why is it 無料といっても and not 無料だといっても?

With nouns/na-adjectives before といっても, the だ is often omitted in this set phrase. Both are grammatical; 無料だといっても is a bit heavier/explicit, while 無料といっても is smoother. Don’t use polite です before といっても; use the plain form.

What does the particle と mean here?

It’s the quotative と, marking what’s “said/called.” Even when no one is literally speaking, it turns the preceding word/clause into the content of “say/call”: X と言っても ≈ “even though it’s called X.”

Why is は used after 会議 but が after 予約?

会議は sets “the meeting/conference” as the topic—the thing being talked about.
予約が marks the subject of 必要だ (“to be necessary”), i.e., “a reservation is what’s necessary.”
If you say 予約は必要です, you add contrast/emphasis to 予約 (“at least the reservation is necessary”), while 予約が必要です simply states the requirement.

Why not 予約を必要です?

必要 is a noun/na-adjective that takes が (or は) for what is needed: Xが必要だ. Say 予約が必要です or 予約する必要があります, not 予約を必要です. Use を only with verbs like 必要とする (“to require”), which is formal/literary.

What part of speech is 無料? Can I say 無料な?

無料 is a noun meaning “free of charge.” As a predicate: 無料だ／無料です. As a modifier: 無料のN (e.g., 無料の配布物). 無料な exists but is rare/awkward in modern usage; prefer 無料の.

Who is doing the “saying” in といっても?

It’s often impersonal: “it’s said/advertised/considered.” Japanese commonly omits the agent when it’s obvious or unimportant. You can make it explicit: 広告では無料だといっても… or 無料だとされていても….

Is といっても the same as けど/が or でも?

They all mark contrast, but nuances differ:

Xといっても Y: “Admittedly/so-called X, but Y” (qualifies X).
Xけど/が Y: plain “although X, Y,” no “as they say” feel.
Nでも Y: “Even if/though N, Y,” a straightforward concession.
Examples: 会議は無料だけど、予約が必要です (neutral contrast). 会議は無料でも、予約が必要です (pure concession). といっても adds the “so-called” nuance.

Can I rephrase 予約が必要です?

Common alternatives (choose by tone/politeness):

予約がいります／要ります (casual/neutral).
予約しなければなりません／予約しないといけません (obligation).
予約する必要があります (polite, clear).
予約が必要となります／予約が必須です (formal/announcement-like).

Why end with です and not だ?

です is polite and fits notices or neutral conversation. だ is plain/informal (予約が必要だ). Very formal announcements may use 予約が必要となっております.

Are the spaces and comma normal? How is は pronounced here?

Standard Japanese doesn’t use spaces between words; the spaces are for learners.
The comma 、 is normal punctuation.
The topic particle は is pronounced “wa.” So 会議は is read かいぎわ.

Could I say 会議が無料といっても instead of 会議は無料といっても?

You can, but は is more natural here because the sentence contrasts “free” with the reservation requirement; は sets up that contrastive topic. が makes 会議 the grammatical subject (“the meeting is free”), which fits answers like “Which meeting is free?” but weakens the contrastive feel.