Jimmy Webb didn't write which of these songs?

Jimmy Webb (b. August 1946) didn't write the 1970 song "We've Only Just Begun". This is a single recording which was sung by The Carpenters. It was written by Roger Nichols (music) and Paul Williams (lyrics). It has been ranked No. 414 on Rolling Stone magazine's list of "The 500 Greatest Songs of All Time."

"We've Only Just Begun" was originally recorded by Smokey Roberds, a friend of Nichols, singing under the name of "Freddie Allen". It debuted within a wedding-themed TV commercial for Crocker National Bank in California in the winter of 1970. Williams is the person singing the vocals. Hal Riney of the San Francisco-based advertising agency Hal Riney & Partners had commissioned the song to help Crocker appeal to young people as clients.

Richard Carpenter of The Carpenters saw the bank's TV commercial and guessed that Williams was the vocalist; both men at the time were under contract to A&M Records. Richard then asked Paul if a full-length song version was available. Williams was later able to provide a complete song version for Carpenter's use.

"By the Time I Get to Phoenix", a 1967 country song, "Wichita Lineman", a 1968 pop–country song, and "All I Know", a 1973 easy listening–orchestral pop song were all songs that were written by the American songwriter Jimmy Webb.