Human - humane
These two were interchangeable until about the 17th century. The two spellings (and pronunciations) represent distinct meanings. Human is the more general; humane has a narrower set of meanings. Be careful not to use the wrong spelling.
Both adjectives form an abstract noun, humanity. This can mean either 'the state of being human' (i.e. all members of homo sapiens) or 'the state of being humane' (i.e. 'being nice to people or animals').
- human as a noun means a member of our species - homo sapiens: a man or woman, or a child with the potential to be a man or a woman. human is pronounced, whether adjective or noun, with the stress on the first syllable, and a very vague vowel (the schwa) in the second syllable, 'HYOU-man', IPA: /ˈhjuː mən/. Human is the common English adjective to describe our species - and things that human beings have done, or that belong to human beings.
- humane, pronounced with the stress on the second syllable, is like 'main' ('hyou=MAIN', IPA: /hju ˈmeɪn/. In earlier times, humane meant "Characterized by such behaviour or disposition towards others as befits a man." (OED, 1989). It has become limited to a particular set of meanings of what 'befits a man'. humane now means in most contexts "Marked by sympathy with and consideration for the needs and distresses of others; feeling or showing compassion and tenderness towards human beings and the lower animals; kind, benevolent." (OED). More simply, it means 'being nice to people and animals'. We can even have a humane killer, which is the least distressing way in which a vet can 'put down' (i.e. kill) a suffering animal; more oddly, weapons experts talk of humane bullets, and diplomats have outlawed inhumane weapons (those which cause more suffering than they need to do, such as saw-edged bayonets, various forms of fire, and chemical weapons). Humane is pronounced differently from human. In humane, the stress is on the second syllable, whose vowel rhymes with "plane" and "main": 'hyou-MAIN'.
humane has a second meaning that students may well come across. In terms of studies, it was traditionally used to describe branches of learning "which tend to humanize or refine" (OED). These were thought of mostly as what we now often call 'the [study of] Classics': in other words, Latin and ancient Greek language, literature, philosophy and history. At Oxford University, this is still called Lit. Hum. (abbreviated from the Latin Literae Humaniores, ~ 'humane letters or literature').
Nowadays we often use the term 'the Humanities' in a similar way to mean a group of subjects (defined differently in different institutions) which are felt to be civilising. They often include foreign languages, English and foreign literatures, History, Geography, the Arts, Philosophy and Theology.
The two meanings of humane may be illustrated by this sentence: "Despite Hunter's cruel discipline, Johnson came to respect his ability to drum Latin into his charges, and attributed much of his humane learning to the thorough grounding he received from the headmaster", where obviously the teacher was not humane in the sense of being 'kind or benevolent' (he beat the boys, too often and too hard); but he taught them the basics of humane (or 'refined') study. (Taken from the ODNB article on Samuel Johnson, on-line at http://www.oxforddnb.com/view/article/14918?docPos=4 (accessed 04-08-06))