Watched Lecture 3 of 36: Introduction to the Subjunctive Mood by Hans-Friedrich Mueller from Latin 101: Learning a Classical Language | The Great Courses

See how the long vowel a" is the key to the present subjunctive mood in verbs such as pono (I place). The subjunctive expresses doubt or potential, and you explore its use by the poet Catullus in one of the most famous love poems to survive from the ancient world."

“Linguam Latīnam discunt, ut in Rōmā antīquā vīvant.” They learn the Latin language, so that they may live in ancient Rome. Intellectually that is. As a way to forget about the present troubles, which is actually a pretty good reason to learn Latin.

How did he know!?!

Notes on my wiki.