Learn Dutch: Als de blinde valt, help ik hem. - If the blind person falls, I help him.

Here, the adjective blind is turned into a noun to mean 'the blind person'. When you use an adjective as a noun to refer to a person, you add an -e to the base adjective. You do not need to add a word like persoon or man after it.

Why is the word order help ik instead of ik help?

The entire if-clause (Als de blinde valt) occupies the first position of the overall sentence. Because of the Dutch verb-second rule, the main verb (help) must come immediately after this clause, forcing the subject (ik) to swap places with the verb.

Does de blinde specifically mean a man because of the word hem?

Not necessarily. De blinde can refer to any blind person. However, when referring to a generic person in Dutch, the masculine pronoun hem is often used as the default. If you were talking about a specific woman, you would use haar instead.

Can als mean 'when' here?

Yes, als means both 'if' and 'when'. Depending on the context, this sentence could just as easily mean: 'When the blind person falls, I help him.'