question about the past perfect

[at.ouchen]

Good day

in the Manhattan SC page 107 we have

Right: She PLAYED with her friends when the babysitter ARRIVED
In this case, the action played took place after the babysitter arrived. Both actions are in the
Simple Past and express equal levels of importance

but in page 261 (The exercice section of the advanced part)
Wrong :When he swam across the lake, he lay down on the far shore and relaxed in the sunshine until
was thoroughly dry.
Swam (simple past tense) should be had swum (past perfect tense). The verbs lay and "!axed are in the simple past tense. Because the swimming must have happened before the lying and relaxing on the for shore,
the past perfect had swum is more appropriate than the simple past swam.
Correction: When he had swum acros& the lake, he lay down on the far shore and relaxed in the
sunshine until he was thoroughly dry.
According to first explanation, the second sentence should be correct as well???!!!!
Many thanks in advance

[RonPurewal]

You're correct. "Swam" conveys the rather absurd idea that he lay down and relaxed while swimming! Nice catch.

Your version works.

"After he swam..." also works, and would be much more likely to show up in well-written English.
(There's nothing wrong with your version; it's just that "swum" is such a ... weird word. It's not a word that most writers would ever use; it's just too weird.)