Ago vs Since

Ago vs. Since

Both words speak of the past, and they are often used interchangeably.

Ago - from the present to the past. It is used after the word or phrase it modifies, especially with the simple past tense, not with the perfect tense.

e.g - It happened a few minutes ago.

Since - from the past to the present. It is used with the present or past perfect tense.

e.g - I haven't eaten since breakfast.