"verbs: past tenses -t/-ed Both forms of ending are acceptable in British English, but the -t form is dominant
burnt, learnt, speltwhereas American English uses -ed: burned, learned, spelled. Contrarily, British English uses -ed for the past tense and the past participle of certain verbs
quitted, sweatedwhile American English uses the infinitive spelling--quit, sweat. Some verbs have a different form of past tense and past participle, eg, the past tense of dive is dived in British English but dove in American English."
(The Economist Style Guide, 10th ed. Profile Books, 2010)
For example:
"The dog leapt onto the table" (simple past)
"The dog had leaped onto the table" (present perfect)
"The dog had leaped onto the table" (past perfect)
I can't figure out whether these changes were implicit in Webster's new rules of spelling (1828), or if they have since creeped into usage. (NB creeped, not crept!) I speak English as a first language with what the Americans call a British accent, although I'm an African who has never been to England. Whilst teaching English in Mexico (with several U.S. American colleagues), I found American English very lacking in vowel difference - I blame Webster directly for this. (Reading "color" instead of "colour", etc: I pronounce the "our" at the end of "colour" and "valour" differently to the way I pronounce the "or" at the end of "motor", "rector" etc.) However, with reference to this question, the above is a concise explanation that they are not the same and that there is indeed a difference in pronounciation if the intention is to enunciate clearly.