You should encourage your players to talk to each other on the field. There are some typical terms that are used in certain circumstances. Some of these are:
The most useful of the above is "Keeper". It's hard to teach these. Perhaps the best thing is to introduce them by U-10 or U-12 & encourage talking in general. Small-sided games encourage talking & are another reason they are so beneficial. (See "Show For The Ball").
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