It's probably a good thing that even in politics, actions speak louder than words. Otherwise it would be easy to believe that Mayor Walter E. Washington is actually in favor of the marijuana decrimilization bill that he voted last week - or at least confused it - rather than out to score afew politicals points.

To hear the mayor on television, on woild believe that the measure, proposed by Counciman David A. Clarke (D-one), flung open the door to further drug use by youngters in the city by lessening the criminal penalties for the use, possession, distribution or cultivation of small amounts of marijuana.

"What I had to look at was I thought was so basic, and that is with the children I saw, and this bill didn't deal with juveniles. I wasn't sure this thing could help in any way," the mayor said a television call-in show last week.

On that show, he didn't mention his support of decriminalization of marijuana for adults. but that support was noted in his veto message. "The measure also proposes a change in the law in respect to the occasional use of small amounts of marijuana. I am not opposed to these provisions insofar as they pertain to adults," the message said.

"However, I do not believe that the same provision should be made applicable to juveniles. Unfortunately, the measure does not distinguish between the use of marijuana by adults or juveniles, "Washington saif.

It was that asserrtion which angered Clarke, primarily because the record of proceedings on the bill - as well as some key but slightly ambiguous wording in it - strongly suggests that the decriminalization provisions were never meant to pertain to minors.

"These procedures would not apply to juveniles, who would continue to be subject to detention as they are now," Clarke said, when the bill was introduced on Jan. 18. In the measure itself, the section providing for the lesser penalties begins with the words," Anyone who is 18 years of age or over. . .

Clarke contended that his wordingmade it clear that only adults would be affected, Corporation Counsel John R. Richer Jr., on whose analysis the veto was partially based (Richer actually wrote the veto message) disagreed. In another of the bill, Richer said, Clarke had effectively eliminated all of the old penalities for juvenile marijuana use, and by making the new ones applicable only to adults, had technically proposed to penalties for juvenile marijuana use.

In less political times, lawyers for both sides might have quietly gotten together and worked out mutual-satisfactory language. In fac, Clarke was even assured by Rishe less than a month ago that the corporation counsel would not recommend a veto based on lighter penalties for juveniles. (At the time he gave that assurance, Risher later said, he was under the mistaken impression that more satisfactory wording had been inserted).

Clarke was so upset by the mayor's action that he threw down the political gauntlet. "I hereby call upon the mayor to say what it is that he will support," Clarke said after the veto. To date, the mayor has not bothered to pick it up.

Marijuana decriminalization is a touchy political issue and the mayor has won for the time being. Clarke may not like the way Washington reads bills, but any political observer can't help to admire the way that, based on this veto and a similar rehection of an emergency rent control law Oct. 25, the mayor has learned quiet effectively how to count to nine - the number of Council votes needed to override a veto.

Rhetorically riding both sides of an issue is nothing new in politics. In last year's Montgomery County congressional race, for example, Republican Newton I. Steers acknowledged having four mutually contradictory public stances on abortion and the use of federal funds for abortions. Steers won the election.