Learn Portuguese (Portugal): Ainda bem que se podem usar as enciclopédias antigas. - It is a good thing that the old encyclopedias can be used.

This sentence uses the passive se. In this structure, the items being used (as enciclopédias antigas) act as the grammatical subject of the sentence, rather than the direct object. Since the encyclopedias are plural, the modal verb poder must be conjugated in the plural to agree with them.

Why does se come before podem instead of being attached to it with a hyphen?

The word que is a strong pronoun "magnet." It forces the pronoun se to move right in front of the conjugated verb podem. If the sentence didn't have que, it would start with the verb and use a hyphen, like Podem-se usar as enciclopédias antigas.

Could I say que podem usar-se instead, attaching the pronoun to the infinitive?

No, because the magnet word que pulls the pronoun to the front of the entire verb phrase. In European Portuguese, when a magnet word requires the pronoun to come before the verb, it goes before the conjugated auxiliary verb (podem), and you cannot attach it to the infinitive (usar) instead.

Does ainda bem que literally mean "still well that"?