What letter changes the sound of the vowel 'a' when following specific phonetic rules?

The letter that changes the sound of the vowel 'a' according to specific phonetic rules is 'w'. When 'w' follows 'a' in certain contexts, it often alters the way the 'a' is pronounced, leading to different sounds. For example, in words like "was," the 'a' sounds different than it would in words where 'w' is not present.

This phenomenon occurs due to the combination of letters influencing vowel sounds based on their position and interaction in word structures. Therefore, the presence of 'w' next to 'a' can indicate a specific pronunciation pattern that learners need to recognize as they become more familiar with phonetic structures.

Understanding how letters affect vowel sounds is crucial for effective reading and spelling, particularly within Multi-Sensory Structured Language Education, as students learn to decode and encode words efficiently.