Learn Farsi: خستگی رفت و آمد از تهران تا کرج طاقت‌فرسا است. - The fatigue of commuting from Tehran to Karaj is grueling.

In this sentence, az Tehrân tâ Karaj marks a physical spatial boundary meaning 'from Tehran to Karaj'. You can use the exact same az ... tâ ... structure for time boundaries too, such as az sobh tâ shab (from morning to night).

What is the literal translation of raft-o-âmad (commuting)?

It literally means 'went and came'. It is a compound noun made by joining the past stems of raftan (to go) and âmadan (to come) with the conjunction o (and). This is the standard Farsi way to refer to commuting or the coming and going of people.

How do we grammatically connect khastegi (fatigue) to raft-o-âmad (commuting) when reading?

You need an Ezafe to say 'the fatigue OF commuting'. Because khastegi ends in a vowel (the -i sound), the Ezafe is pronounced as a -ye sound, making it khastegi-ye raft-o-âmad. As is typical, this connector is not written out as a separate letter in the Farsi script.

How do we break down the compound word tâqat-farsâ (grueling)?

This is a compound adjective. Tâqat means 'endurance' or 'patience', and farsâ comes from a verb root meaning 'wearing out' or 'consuming'. So tâqat-farsâ literally describes something that wears out your endurance, which is why it perfectly translates to 'grueling' or 'exhausting'.