An American wrote this sentence the other day in an email message to my wife.

Having lived several years in England, she told me that it looked odd to her.

She would have written “Photos are always welcomed.” — with a “d” at the end.

In other words, she sees this as a passive-voice sentence (in which the actor is not specified).

The active-voice form of the sentence could be “We always welcome photos.”

Given that speaking or writing in the passive voice requires the use of the past participle of a verb, the passive-voice form of “We always welcome photos.” requires the past participle “welcomed” — with a “d” at the end.

I believe that the American tendency to drop the “d” from the past participle “welcomed” in “Photos are always welcomed.” is consistent with my “Devolution toward Simpler” linguistic hypothesis.

It is simpler to say “welcome” (without the “d”) than to say “welcomed” (with the “d”). And, even if someone says “welcomed” (with the “d”), many American listeners will not hear the “d” and will write “welcome” (without the “d”) instead.