The -s ending is pronounced three ways, according to the ending of the verb.
after -ch, -sh, -s, -x, -z endings.
teaches, washes, kisses, boxes, buzzes.
after voiceless p, t, k, or f.
stops, hits, looks, laughs.
after voiced consonant endings.
以发音的辅音为结尾
calls, listens, plays, sounds, runs.
The -ed ending is pronounced three ways, according to the ending of the verb.
after -d and -t endings.
needed, insisted, waited, wanted.
after voiceless endings.
boxed, helped, looked, watched, washed.
after voiced endings.
carried, breathed, called, climbed, played, listened.
书名: Mosaic1-Grammar 4th Edition
作者: Patricia K.Werner/Lou Spaventa
章节: Chapter1 - New Challenges
页码: p17
原文：https://www.cnblogs.com/puwen/p/10390211.html