Cary Grant was one of those great Hollywood stars about whom it was seldom said that he could do anything. He could do a lot of things, up to a point, as the Hollywood community seemed to agree when it dutifully nominated him for an Oscar for his performance as the Cockney wanderer in the exceedingly poetic ''None but the Lonely Heart'' (1944).

Yet, for Cary Grant to do ''anything'' was to miss the point (and waste the talents) of this most blithe of film actors, a man whose comic and romantic performances were as complex as the internal rhyme schemes of a Cole Porter lyric - and seemed as effortless. Though Mr. Grant played Cole Porter in ''Night and Day'' (1946), a leaden, conventional, utterly fanciful screen biography, it was in his superb comedies - from ''The Awful Truth'' (1937) to ''North by Northwest'' (1959) - that the actor best demonstrated the wit and grace exemplified by Porter's words and music.

Like the composer's work, Mr. Grant's isn't easily analyzed. It appears simply to have happened. The instinct and intelligence that make it possible are assumed without question. This is probably why he never received an Oscar for a particular performance, though twice nominated (the other time for ''Penny Serenade'' 1941). Both nominations were for not especially characteristic roles, which is Hollywood's usual, hapless way of measuring talent. A Lightness of Heart and Touch To ask Mr. Grant to do a mood piece like ''None but the Lonely Heart'' or a solemn-faced, period spectacle like ''The Pride and the Passion'' (1957) was to anesthetize a large part of the actor's personality. He could do these films more than creditably, but it was like asking Cole Porter to write a hymn on behalf of the beautification of America: extraordinary natural resources were being left unused.

With the exception of Fred Astaire, Mr. Grant, more than any of his equally popular contemporaries (Clark Gable, Spencer Tracy, James Stewart, John Wayne and Humphrey Bogart), possessed a lightness of heart and touch that, in his case, was far more adaptable than was ever immediately apparent.

Compare his brilliantly funny work as the ruthless city editor, Walter Burns, in ''His Girl Friday'' (1940), Howard Hawks's gender-bending adaptation of ''The Front Page,'' with his cool portrayal of the American agent in Alfred Hitchcock's ''Notorious'' (1946). Both characters look like Cary Grant and sound like Cary Grant, but they're completely different men, sharing only what might be called a profound urbanity, which is built into the nature of the actor as he appears on the screen.
This had nothing to do with the dinner jackets he wore with such ease. You can see hints of it even in his first film with Mae West, ''She Done Him Wrong'' (1933), in which he wears a Salvation Army uniform from beginning to end. It's fully realized by the time of ''Gunga Din'' and ''Only Angels Have Wings,'' both essentially adventure films and both made in 1939, and was to remain undiminished throughout the rest of his long career, particularly in his last two Hitchcock films, ''To Catch a Thief'' (1955) and ''North by Northwest.'' Making Other Actors Look Good, Too Look at his films today and you'll discover a remarkably supple actor who, without taking a back seat to anybody, manages to make everyone around him look almost as good as he is. He worked with most of the screen's finest actresses, but none of them was ever quite so romantic or funny or both as they were with him - Constance Bennett, Irene Dunne, Rosalind Russell, Ingrid Bergman, Eva Marie Saint, Grace Kelly and Ann Sheridan, with whom he co-starred in Hawks's postwar farce, ''I Was a Male War Bride'' (1949).

Even Katharine Hepburn, whose films with Spencer Tracy are a sort of mini-genre in themselves, achieved an ease (and a certain madness) of style in her films with Mr. Grant that can't be compared with her work with Tracy.

This wasn't self-effacement on Mr. Grant's part. Rather it's a reflection of the completely mysterious presence he possessed as an actor in a mechanical medium that adored him, and which, in more than 50 years, has discovered no one who comes anywhere near him. It's one measure of his personality that, as was not the case with lesser actors, it has always appeared to be so completely revealed in his performances that gossip about his private life has seemed superfluous.

In Mr. Grant's performances, as in Cole Porter's songs, something of the debonair spirit of the depressed 1930's remains forever fixed in a time that never dates.