What terms are used to distinguish phonemes based on their placement in words?

The terms that accurately distinguish phonemes based on their placement in words are "beginning," "medial," and "ending" phonemes. These terms refer specifically to the locations of phonemes within a word.

Beginning phonemes are those that occur at the start of a word, medial phonemes are situated in the middle of a word, and ending phonemes are found at the end. This classification is essential in understanding how words are structured and is commonly used in phonics instruction to help learners recognize and manipulate sounds in spoken language.

The other options, while they may refer to different aspects of phonological awareness or sound properties, do not directly denote the position of phonemes within words. For instance, terms like "onset" and "rime" relate to syllable structure rather than placement within the entire word. "Initial," "medial," and "terminal sounds" could also describe phoneme placement, but "beginning," "medial," and "ending" are more commonly recognized in the educational context of phonetics. "Front, middle, and back sounds" tends to pertain to articulatory features rather than specific placement within word structures.