Errors & Omissions: We, as a seafaring nation, should get the terminology right

Last Saturday's paper carried a full-page photograph of the Gloria, the Colombian navy's sail training ship, passing through Tower Bridge. A magnificent spectacle, but the caption lowered the tone a bit at one point, when it said: "The Gloria's central mast measures 133ft."

The masts of a three-masted sailing ship are called the foremast, the mainmast (not the central mast) and the mizzen mast. This is more than a point of seagoing pedantry, for it touches on the English language's rich heritage of maritime metaphor. The mainmast gives its name to the mainstay, a substantial item of rigging which holds the mainmast up – hence, the principal support of anything. In fact, the Gloria's mainstay is clearly visible in the picture.

Checkmate: A Timeline feature on Wednesday dealt with the history of board games. It was illustrated with an old depiction of a medieval man and woman playing chess. The caption said: "Othon, the 14th-century Marquis de Bradebourg, plays chess." And, indeed that is what it says on an inscription on the illustration itself, so that must be true. Yes, but what nobody seems to have spotted, either in this office or the agency that supplied the picture, is that while the inscription is in French, the "marquis" is German.

We don't normally give the names of German people in French. Somebody should have had the gumption to translate this one into English: "Otto, Margrave of Brandenburg."

Journalese: This is from a news story published on Wednesday; "As worshippers in other Muslim nations celebrated the festival of Eid al-Fitr ... Indonesia – the world's most populous Islamic country – sparked confusion by declaring that the Moon was too low in the sky for festivities to commence there." It seems that in newspapers nothing is ever caused, or occasioned, or provoked, but always "sparked".

Once upon a time, "sparked" was a vivid metaphor, evoking the image of a spark igniting a store of gunpowder. And it had a precise application too. To spark something was not to cause it but to set it off. The disaster had to be ready to happen, needing only a spark. For example, we can all argue about the causes of the recent looting – poverty, consumerism, lack of discipline, family breakdown – but everyone agrees that it was sparked by a shooting in Tottenham. Unfortunately, such fine discrimination in the figurative use of "spark" is no longer possible. The word has been corrupted into a redundant synonym for "cause". Time to snuff it out.

Death of a word: "Lyndhurst had been reticent about doing the prequel, but as soon as he read John Sullivan's script he signed the dotted line." So said a profile of the actor Nicholas Lyndhurst in last Saturday's magazine.

There are, or used to be until recently, two different words, "reluctant" and "reticent". "Reluctant" means not very willing to do something: "reticent" means reluctant to say something. More and more, you find "reticent" used in place of "reluctant". Any pair of words of vaguely similar sound and meaning are in danger of being merged. Poor old "reluctant" seems to be losing the battle for survival. A pity.

Stay single: "For decades their chugging and chiming has signalled the start of summer and feeding time for generations of children armed with small change and sweet tooths." That sentence, which began a feature article about ice cream vans on Wednesday, is carefully written and contains some nice effects. That makes you think "sweet tooths" may be a deliberate oddity. But I am afraid it is just too odd.

The reader's mind just revolts at the sight of "tooths". The plural of "tooth" is "teeth". But "sweet teeth" would be wrong as well, for that would make the reader think of literal, physical teeth. "A sweet tooth" means a taste for sweet things; it is a manner of speaking, an image to express an abstract quality. So it can be ascribed to more than one person, while itself remaining singular. "Children armed with small change and a sweet tooth" is perfectly all right.