Explain the pronunciation of some letters in the Spanish language. O B and V C Ch H J K L LL O is pronounced like the second o in the word 'roubo'....

Explain the pronunciation of some letters in the Spanish language.
O
B and V
C
Ch
H
J
K
L
LL
O is pronounced like the second o in the word 'roubo'. Its sound is not as closed as in 'tarô' and not as open as in 'retórica'. As a general rule, in cases where it forms a free syllable (not followed by another consonant), the o will have a more closed sound, but not completely closed. For example, 'ro-bo' will have a more open sound in 'bosque' and 'sol'. The o does not have the sound of u, as sometimes some people in Brazil pronounce it.
B and V have the same sound in Spanish, both sound like the b in Portuguese. The sound of the letter b and v is practically the same as the b in Portuguese, being only a little softer, with less bilabial pressure. Therefore, there are no differences in pronouncing b or v in 'boca' and 'vaca' (pronounced 'baca'). As a general rule, the sound of the letter v and b resembles the b in Portuguese at the beginning of words and before r (example: 'hombre', 'vuelta'). In other situations, its sound is softer but never reaches the sound of v in Portuguese.
The sound of the letter C is the same as in Portuguese when it is next to a vowel. Its sound is stronger when it is close to a, o, and u, as in the word 'captar'. The softer sonority varies from country to country, in Spain, it is a sound similar to the 'th' in English ('theory'), here in South America, its sound is 'ss'. When it comes before the syllables 'ce' and 'ci', it will have a pronunciation with the sound of a dry k, for example, 'accionista' (akcionista).
Ch is typical of Spanish, attention that it is not two letters c and h, it is one letter only. Its sound is dry, like in the word 'tchau'. Thus, we have the words 'ducha' (dutcha), 'derecha' (deretcha), 'estrecho' (estretcho).
H is generally silent, and it is not pronounced in the word, for example: 'ahijado', 'buho', 'honesto', 'hada'. When it comes next to 'ue', the sound becomes similar to 'gue', so 'hueso' is pronounced as 'gueso'. But for this case, there are also regional differences, so we could have 'huelga' pronounced as 'guelga' or 'uelga'.
J requires a lot of attention when we say words that have it. Its sound is similar to 'rr' (as pronounced by cariocas) as in the word 'carro', at the beginning of the word, it has the sound of 'r', as in 'raiz'. Thus, we have 'javalí' (rabalí), 'jamás' (ramás), 'joven' (roben). Another comparison would be with the sound of 'h' in English in the words 'house', 'hit', 'home'.
K is normally used in words of foreign or Greek origin. There are no major difficulties regarding its use. Its sound is like the c before a, o, u in Portuguese, that is, ca, co, cu, examples: caber, cobrar, cultura. Before e and i, it has the sound of 'que' and 'qui', respectively, for example, 'kilo', 'kilómetro'.
L sometimes generates pronunciation problems because in many regions of Brazil, when it comes at the end of the word, it is pronounced as u or ul. The l must be pronounced dry and well marked (as in 'óleo'), so the word 'sal' should not be pronounced as 'saul' or 'sau', thus we have 'papel' and not 'papeu', 'miel' and not 'mieu'. So don't forget, l has the sound of l and not u.
LL is another typical letter of Spanish. Like ch, it is one letter only, not two l's. Its sound undergoes some variations according to some regions. In Argentina and Uruguay, for example, it is pronounced in a more loaded way, with a sound similar to the letter J in the word 'jornal'. In other countries, its sound is softer, being pronounced with