Learn Arabic (Modern Standard): هذه الأعوام والأشهر سريعة.

In Arabic, all non-human plurals (like years and months) are grammatically treated as feminine singular. Because of this rule, we use the feminine singular word هذه instead of a plural word like هؤلاء.

How do we get the plural الأعوام (the years) from its singular form?

The singular is عام (year). To make it plural, it doesn't take a regular suffix. Instead, the word "breaks" and changes its internal shape to become أعوام. This specific broken plural pattern is very common.

Is الأشهر (the months) also a broken plural?

Yes! The singular is شهر (month), and its broken plural is أشهر. Notice how both أعوام and أشهر start with an extra Alif letter. This is a great hint that you are looking at a broken plural.

Why does the adjective سريعة (fast) end with the feminine marker (ة)?

This is another example of the non-human plural rule in action! Since the plural subjects (the years and months) act like a single female entity grammatically, the adjective describing them must also be in the feminine singular form.