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Open the tips window on the far right side of the Scripts Area on your Scratch editor and select the block you want help for via the "Block" sub-tab. This produces information which explains how the blocks work and gives examples on how to use them. Another alternative is to select the "?" tool at the top of the program and click on the desired block.
The tips window

You can also search the Scratch Wiki. See the list of blocks.

Scratch 1.4

Archive.png This article or section documents a feature not included in the current version of Scratch (2.0). It is only useful from a historical perspective.
Main article: Help (blocks) (1.4)

Right-click on the block and choose "help". This produces a help dialog, which explains how the blocks work and gives examples on how to use them. You may also get a step by step intro, showing you the basics.

See Also