Trente through trente-neuf, then quarante. Same connector pattern as the twenties: et un on the unit 1, hyphens on units 2 through 9. No vigesimal surprises in this range.
Trente. Pronounced /tʁɑ̃t/. Stable across contexts; the final t is voiced.
How do you say 31 in French?
Trente et un. Same et-un connector as 21 (vingt et un). With hyphens (trente-et-un) since the 1990 rectifications; both accepted.
How do you say 35 in French?
Trente-cinq. Hyphen, no connector. The cinq keeps its full /sɛ̃k/ pronunciation in this compound because cinq sits inside the number, not at the end before a noun.
Is there liaison in trente-neuf?
Within the compound itself, no liaison: /tʁɑ̃t.noef/. Before a vowel-initial noun, however, the t of trente carries: trente-neuf ans = /tʁɑ̃t.noev‿ɑ̃/ (with the f-to-v shift on neuf before ans).