Latin consonants had essentially the same sounds as the English consonants with the following exceptions:

bs and bt were pronounced ps and pt: (urbs, obtineō); otherwise Latin b had the same sound as our English letter b : bibēbant.

Latin c (English c) was always hard as in can, never soft as in city: cum, cīvis, facilis.

g was always hard as in get, never soft as in gem: glōria, gerō. When it appeared before n, the letter g represented a nasalized ng sound as in hangnail: magnus.

h was a breathing sound, as in English, only less harshly pronounced: hic, haec.

Latin i (English i) represented both a vowel and a consonant sound. i usually functioned as a consonant with the sound of y as in yes when used before a vowel at the beginning of a word: iūstus

Between two vowels within a word i served in double capacity: as the vowel i forming a diphthong with the preceding vowel, and as the consonant like English y: reiectus ( = rei yectus) maior ( = mai yor), cuius ( = cui yus.) Otherwise it was usually a vowel.

Consonantal i regularly appears in English derivatives as a j, a letter added to the alphabet in the Middle Ages; hence maior = major, Iūlius = Julius.

m usually had the sound it has in English, pronounced with the lips closed: monet. There is some evidence, however, that in at least certain instances final m, that is, m at the end of a word, following a vowel, was pronounced with the lips open, producing a nasalization of the preceding vowel: tum, etiam.

q, as in English, is always followed by consonantal u, the combination having the sound kw: quid, quoque.

r was trilled; the Romans called it the littera canīna, because its sound suggested the snarling of a dog: Rōma, cūrāre.

s was always voiceless as in see, never voiced as in our word ease: sed, posuissēs, mīsistis.

t always had the sound of t as in tired, never of sh as in nation or ch as in mention: taciturnitās, nātiōnem, mentiōnem.

v had the sound of our w: vīvō, vīnum.

x had the sound of ks as in axle, not of gz as in exert: mixtum, exerceō.

ch represented Greek chi and had the sound of ckh in block head, not of ch in church: chorus, Archilochus.

ph represented Greek phi and had the sound of ph in uphill, not of ph in our pronunciation of philosophy: philosophia.

th represented Greek theta and had the sound of th in hot house, not of th in thin or the: theatrum.

The Romans quite appropriately pronounced double consonants as two separate consonants; we in our haste usually render them as a single consonant.

For instance, the rr in the Latin word currant was pronounced as two separate r's, like the two r's in the cur ran; likewise the tt in admittent sounded like the two t's in admit ten.