Scope

The scope fallacy is caused by improperly changing or misrepresenting the scope of a phrase.

Example:

Every concerned citizen who believes that someone living in the US is a terrorist should make a report to the authorities. But Shelley told me herself that she believes there are terrorists living in the US, yet she hasn't made any reports. So, she must not be a concerned citizen.

The first sentence has ambiguous scope. It was probably originally meant in this sense: Every concerned citizen who believes (of someone that this person is living in the US and is a terrorist) should make a report to the authorities. But the speaker is clearly taking the sentence in its other, less plausible sense: Every concerned citizen who believes (that there is someone or other living in the US who is a terrorist) should make a report to the authorities. Scope fallacies usually are amphibolies.

Amphiboly

This is an error due to taking a grammatically ambiguous phrase in two different ways during the reasoning.

Example:

In a cartoon, two elephants are driving their car down the road in India. They say, "We've better not get out here," as they pass a sign saying:

ELEPHANTS
PLEASE STAY IN YOUR CAR

Upon one grammatical construction of the sign, the pronoun "YOUR" refers to the elephants in the car, but on another construction it refers to those humans who are driving cars in the vicinity. Unlike equivocation, which is due to multiple meanings of a phrase, amphiboly is due to syntactic ambiguity, ambiguity caused by alternative ways of taking the grammar.