Hi Pat,

 

As you know Pat the g can be sounded as in gate or goat or as an h sound, as in girasol.

 

 

The letter j is also sounded as an h sound as in jardín.

The vowels in Spanish are in 2 groups:
Hard vowels= A, O and U and Soft vowels= I and E.

So in the infinite Proteger, when conjugated in the present, all the endings use the 'h sounding g' because the g is followed by e and e is a soft vowel. However the exception is in the first person singular. Here the g can't be used because protego is g + o and is a hard sound. It wouldn't match the rest of the conjugation. So the 'h sounding j' is used instead= protejo in order to maintain the sound.

The same follows with gir verbs and in the example given here, dirigir.

I hope my explanation isn't too long-winded & confusing and helps a little. 

Here are 2 links that can help...

 

https://progress.lawlessspanish.com/revision/lessons/letters-and-sounds-in-spanish

https://www.lawlessspanish.com/pronunciation/hard-and-soft-vowels/