Step 1: Understand that 'grammar' refers to the rules that define how sentences are structured in a language.
Step 2: Know that 'ambiguity' means something can be understood in more than one way.
Step 3: Combine these ideas to see that 'grammar ambiguity' happens when a sentence can be interpreted in different ways due to its structure.
Step 4: Realize that this means there can be multiple valid ways to break down (or parse) the same sentence.
Step 5: For example, the sentence 'I saw the man with the telescope' can mean different things depending on how you understand the phrase 'with the telescope'.