The throaty sound
The Spanish j is a rasp made far back in the mouth: the back of the tongue rises towards the soft palate and the air scrapes through, with no voice. English has no such letter, but you can get there from a strong, breathy h by adding friction until it rasps, like the ch of Scottish loch or German Bach. In much of Latin America it really is a strong h; in Spain it scrapes. Both are correct.
J: always throaty
Words with J
joven
young
jefe
boss
jamón
ham
rojo
red
The two faces of G
The split will feel familiar: English also softens g in gem and keeps it hard in game. Only the soft value differs: English says the j of jam, Spanish the throaty sound.
Throaty: g before e/i
gente
people
gimnasio
gym
página
page
Hard: g before a/o/u
gato
cat
amigo
friend
grande
big
gue, gui and güe, güi
To keep g hard before e/i, Spanish writes a silent u: gue, gui. English does the same in guess and guitar, so this costs you nothing.
guerra
war
guitarra
guitar
When the u does have to be heard, it gets two dots: ü. Then you say a real gw sound.
pingüino
penguin
vergüenza
shame / embarrassment
Minimal pairs: j against hard g
Hear the difference
gusto
taste / pleasure
justo
fair / exact
gota
drop
jota
the letter J
In full sentences
Listen and repeat
Jorge es joven.
Jorge is young.
La gente trabaja mucho.
People work a lot.
Mi jefe come jamón.
My boss eats ham.
Toco la guitarra.
I play the guitar.