GI - Hee

A "G" before the letter I in Spanish sounds like an English H. So GI becomes "HEE".

For example you would pronounce the word girar (to turn) as "hee-rahr".

The letters GI are pronounces HEE

To remember this we use the following mnemonic:

The GI (as in GI Joe) was a real he-man (GI-hee).