Although it is frequently claimed that different should be followed only by from, not by than, in actual usage both words occur and have for at least 300 years. From is more common today in introducing a phrase, but than is also used: New York speech is different from (or than ) that of Chicago.Than is used to introduce a clause: The stream followed a different course than the map showed. In sentences of this type, from is sometimes used instead of than; when it is, more words are necessary: a different course from the one the map showed. Regardless of the sentence construction, both from and than are standard after different in all varieties of spoken and written American English. In British English to frequently follows different : The early illustrations are very different to the later ones. The use of different in the sense “unusual” is well established in all but the most formal American English: The décor in the new restaurant is really different.
The constructions different from, different to, and different than are all found in the works of writers of English during the past. Nowadays, however, the most widely acceptable preposition to use after different is from . Different to is common in British English, but is considered by some people to be incorrect, or less acceptable. Different than is a standard construction in American English, and has the advantage of conciseness when a clause or phrase follows, as in this result is only slightly different than in the US . As, however, this idiom is not regarded as totally acceptable in British usage, it is preferable either to use different from: this result is only slightly different from that obtained in the US or to rephrase the sentence: this result differs only slightly from that in the US
late 14c., from Old French different (14c.), from Latin differentem (nominative differens) "differing, different," present participle of differre "to set apart" (see differ). Colloquial sense of "special" attested by 1912. Related: Differently.