Learn Farsi: عکس‌ها روی دیوارها است.

To make a noun plural in Farsi, you usually add the suffix ها (hâ) to the end of the word. Here, عکس (aks - picture) becomes عکس‌ها (aks-hâ - pictures), and دیوار (divâr - wall) becomes دیوارها (divâr-hâ - walls).

The English translation says 'The pictures are', but the Farsi sentence ends with است (is). Why isn't it a plural verb?

In Farsi, when the subject of a sentence is inanimate (not a human or an animal), the verb takes the singular form. Since عکس‌ها (pictures) are inanimate objects, we use the singular verb است (ast - is) instead of a plural verb.

How do the words connect in روی دیوارها (on the walls)? Is there a hidden sound?

Yes! The word for 'on' is روی (ru-ye). It connects to the next word using the Ezafe, which is a spoken 'e' or 'ye' sound that links words together. When you read روی دیوارها, you pronounce it as 'ru-ye divâr-hâ'.

In the Farsi script, why doesn't the ها physically touch the letters before it in عکس‌ها and دیوارها?

When typing Farsi, the plural marker ها is usually separated from the noun by a 'half-space' (a tiny gap that prevents letters from joining). You might sometimes see people write them fully connected, but keeping a slight gap like in عکس‌ها is the standard and most readable way to write it.