what abilities does Aptitude Test try to measure?

Aptitude test attempts to measure the learner's aptitude or natural abilities to learn languages|this type of test usually consists of several different tests|which measure respectively the ability to identify and remember sound patterns|in a new language|the ability to identify the grammatical functions of different parts of sentences|the ability to work out meanings without explanation in a new language|and the ability to remember words|rules and so on in a new language.