This has been on my blog fodder list for a while, and here’s the reason why.
Chidanand Rajghatta, a favourite newswriter, recently did a story on which was the hotter chilly – Assam’s little known Naga Jalokia or California’s reigning champ Red Savina. According to his sources, the Jalokia chilly has now climbed the hottest seat by a big margin – 1,001,304 SHUs to Red Savina’s 577, 000 SHUs.
[SHU stands for Scoville Heat Unit, a measure invented by American chemist William Scoville to quantify spice heat.]
During the course of this tear-jerking debate, Rajghatta writes: “Just how hot are Jalokias is evident from the prefixes it has earned – Bhut means ghost, for that’s what it reduces anyone who bites into it; Naga, the alternate prefix, … is said to reflect the tribe’s fiery temperament.”
Now how do we understand the word “alternate”? Here are the options: alternate:
 Occurring by turns; succeeding each other, take turns (verb): “He and his sister alternate washing the dishes.”
 One and then the other; every other, successive (adjective): “Each of the two pharmacies in this town is open on alternate Sundays.” “The zebra has alternate black and white stripes.”
 Substitute, backup (adjective): “If the main road is closed, take an alternate route.”
 Stand-by, backup, understudy (noun): “He attended the seminar not as a delegate but as an alternate.”
The writer obviously uses the word “alternate” in the third sense – Naga is the alternate (substitute) name for the now-famous chilly. This usage is probably widespread in the US, but in the UK and in India this would be using the word in its narrow sense. In India, the preferred word would have been “alternative”. Let’s look at the word “alternative”.
alternative: A choice between two or among more than two things; something remaining to be chosen; choice, option, recourse: “Is there an alternative to going?”
“If he wants to reach Delhi by tonight (to stake his claim for chiefministership?), he has no alternative but to go by plane.”
So “alternate ” means “following by turns, one after the other” or “a substitute or second” or “every other in a series.”It is related to the adjective and means “to go back and forth” or “to change from one state to another and back again repeatedly.”
Example: The captain alternates the two fast bowlers in the slog overs.
Alternative refers to or implies a choice between two things. As a noun, it refers to the other choice. Example: If the flight is grounded, our alternative is to travel by train. (The other choice).
This sentence should throw more light on the word. A utility “plans to freeze its electric rates for five years, and by 2003 will allow all its customers to buy power from alternate sources.” It is clear the writer meant “alternative,” meaning, providing a choice among options. “Alternate” means by turns, or every other, as in “alternate Sundays.”
Verdict: When you talk of choice, use “alternative”. Huge grants have not stopped the farmer suicides in Vidarbha. We need to think of alternative methods of solving this tragedy.
If it is going back and forth, then there is no alternative but to use “alternate”. When he is sozzled, his mood alternates between bluster and self-pity.
Here is the final word: alternate or alternative?
The two words really do have quite separate and distinct meanings: alternate implies the taking of turns, and alternative implies a choice. Start with the verb “to alternate” and carry its meaning over to the adjective alternate. You have a useful modifier that says, in a word, “First this one, then that one,” or, “Now me, then you, then me again, and so on.” Don’t corrupt alternate with any other confusing meaning.
Then take alternative, which means the choosing of one out of two courses; as a noun, it means such a choice (or “option”), and as an adjective, it is a synonym for “substitute”. Limit it to that. Let’s not blow alternately hot and cold on this: the alternative to holding the line (understanding the words to mean the above) is fuzziness.
—William Safire, On Language