The train is coming.

the Determiner

— Used, instead of a, to reference something specific, already known to exist. Compare "I read a book." and "I read the book." — Used with a stress, to show that the word following is special. Are you the John Smith that I went to school with? — Used with an adjective that acts like a noun to mean all of the people concerned The poor are always with us. — Used with superlatives forms of adjectives and adverbs. You are the best.

train Noun

— A long vehicle with many cars that are joined together. A train runs on a track. I took the train from Paris to Frankfurt.

train Verb

— If you train someone, you teach them a particular skill. In school we had computer training and sex education.

is Verb

— A form of the verb be when talking about someone or something else. He is late for class. Is it hot in here?

coming

— adjective (= approaching, forthcoming, upcoming) of the relatively near future the approaching election this coming Thursday the forthcoming holidays the upcoming spring fashions — noun (= advent) arrival that has been awaited (especially of something momentous) the advent of the computer — noun (= approach, approaching) the act of drawing spatially closer to something the hunter's approach scattered the geese — noun (= approach, approaching) the temporal property of becoming nearer in time the approach of winter — noun (= orgasm) the moment of most intense pleasure in sexual intercourse