Learn Portuguese (Portugal): Ainda que não memorizes todo o vocabulário, deves praticar. - Even if you do not memorize all the vocabulary, you must practice.

The phrase ainda que (even if / even though) is a concessive conjunction. It introduces an obstacle that doesn't actually stop the main action from happening. In Portuguese, ainda que always forces the verb that follows it into the subjunctive mood, which is why we use memorizes instead of the regular present tense memorizas.

How is the present subjunctive formed for memorizes?

Memorizar is a regular -ar verb. To form the present subjunctive, you take the eu form of the present tense (memorizo), drop the -o, and add the opposite endings. Because it is an -ar verb, it takes -e endings. For the tu (you) form, that ending is -es, giving us memorizes.

Why does it say todo o vocabulário instead of just todo vocabulário?

In Portuguese, when you want to say 'all the' or 'the whole' regarding a specific thing, you use todo followed by the definite article (o, a, os, as). So, todo o vocabulário means 'all the vocabulary'. If you leave out the article, todo usually translates to 'every'.

Why is deves in the regular present tense (indicative) when the first half of the sentence uses the subjunctive?