/g/ — the G sound as in go, get, big

Main spellings (~99%)

⟨g⟩ ~71%

The letter ⟨g⟩ makes the /g/ sound in most positions, especially before ⟨a⟩, ⟨o⟩, ⟨u⟩, and consonants.

G before E, I, Y: The letter ⟨g⟩ can make either /g/ or /ʤ/ before ⟨e⟩, ⟨i⟩, ⟨y⟩. Compare: get (/g/) vs gentle (/ʤ/), give (/g/) vs giant (/ʤ/).
Doubled consonants: When ⟨gg⟩ appears in the middle of a word, it still makes just one /g/ sound. Examples: bigger, egg, trigger.

Unusual spellings (~1%)

⟨gu⟩

Before ⟨e⟩ or ⟨i⟩, ⟨gu⟩ keeps the /g/ sound (the ⟨u⟩ is silent).

Why GU? The silent ⟨u⟩ in ⟨gu⟩ prevents the ⟨g⟩ from being pronounced as /ʤ/. Without it, "guard" would look like it should rhyme with "jarred."
Two ways to see this: You can think of ⟨gu⟩ as an unusual spelling of /g/, or as a silent ⟨u⟩ after ⟨g⟩ — see the silent U page. Both are valid.

⟨gue⟩

At the end of words, ⟨gue⟩ makes just /g/ (both ⟨u⟩ and ⟨e⟩ are silent).

Two ways to see this: You can think of ⟨gue⟩ as an unusual spelling of /g/, or as a silent ⟨ue⟩ at the end of a word — see the silent U page. Both are valid.

⟨gh⟩

In a few words, ⟨gh⟩ makes /g/.

/g/ vs /ʤ/

Don't confuse /g/ with /ʤ/! Both can be spelled with ⟨g⟩, but they're different sounds. Compare: bag vs badge, rag vs rage, bigger vs badger.