The Doubling Rule states that when a one-syllable word ends with a single vowel followed by a single consonant, the final consonant is doubled before adding a suffix that begins with a vowel (e.g., 'run' becomes 'running').

The word 'hop' becomes 'hopping' when the suffix '-ing' is added.

The word 'sit' becomes 'sitting' because the final 't' is doubled.

For words ending in 'e', the 'e' is dropped before adding '-ing' (e.g., 'make' becomes 'making').

The correct spelling is 'snapping'.

The correct spelling is 'scamming'.

The correct past tense is 'occurred'.