The H Factor

H is a special consonant that can have a variety of sounds, especially when paired with other consonant letters.

At the beginning of words, H is followed by another vowel. Normally, H sounds like a light Spanish J.

For example: hand, help, hill, horse, hunt. (1)

But there are few words, like hour and honest (H followed by O) when the H is silent. (2)

In these case, you have to be careful when using an indefinite article before these H words. For example, we say: a hand but an hour. (3)

On the other hand, H has special relationships with various letters. Some letter combinations always have the same sound, but other combinations can vary a lot. 

Three combinations, whose sound never change, are sh and th and ph.

Sh sounds like : shape, finish or fashion. (4)

Th sounds like : that, faith or other. (5)

Ph sounds like : phantom, graphic or phosphorous. (6)

Ch often sounds like the Spanish CH: chocolate, coach or church. (7)

But ch can also sound like : chemistry, school or ache. (8)

The threesome tch also sounds like at the end of words: batch, catch or watch. (9)

Gh is a little more complicated. 
At the beginning of a word it sounds the same as the English G of gum:  ghost, ghoul or ghastly. (10)

And gh is usually silent at the end of words too: although, dough. (11)

It is also silent before the letter T at the end of words: night, right, caught, bought. (12)
But there are some exceptions, when gh sounds like F at the end of words: laugh, rough, or tough. (13)

And finally, there’s wh, which usually like an English W: what, where, when, why or whale. (14)

But when followed by an O, wh sounds like a Spanish J: who, whose, or whole. (15)