Final answer:
The question asks about identifying letters representing specific consonant sounds in words. Underlining the corresponding letters helps improve spelling skills in English language studies.
Step-by-step explanation:
The student's question is about identifying letters that represent certain consonant sounds in words. This concept is a part of phonics, which is included in English language studies, specifically focusing on spelling and pronunciation. For example, to underline the letter that spells [p] in the word perfect, you would underline the letter 'p' since it represents the consonant sound mentioned. Similarly, in the word behind, the letter to underline that spells [b] is 'b'. When looking at the word itself, the letter that spells [t] is 't'. Lastly, in the word wonderful, the letter that spells [d] is 'd'. It is important to identify the correct letters to improve spelling skills.