"הם לא מחדשים כלום."

Translation: They do not renew anything.

[Ynhockey]

Note for learners: While the verb לחדש can mean 'to renew' like in the tooltips, just as often it means 'to tell something new'. Therefore in many (maybe most) contexts the sentence will actually mean 'They are not telling anything new'.

[IanBiddle]

why is "they are not renewing anything" wrong here?

[AlmogL]

It should be accepted.

[IanBiddle]

many thanks: though as much

[deactivated user]

AM I RIGHT IF I SAY THAT THE מ AT THE BEGINNING OF THESE VERBS ACTUALLY TURNS ADJECTIVES INTO VERBS?

[Ynhockey]

No, this is not the case. It's just a matter of verb construction: the base of the verb is in the construction פִּעֵל (pi'el), i.e. hidesh. The present 3rd person plural is מפעלים, in this case mehadshim.

[deactivated user]

Interesting. Thanks for your comment.

[YardenNB]

As Ynhockey wrote, it's not a general rule, but it's quite often the case. The pi'el template typically means "causing something to happen / to be". So if ישר is "straight", ליישר is "to make straight". Similarly יפה - מייפה, קצר -> מקצר, and many other examples. It's not a general rule, because there are also verbs in this template that don't have such an adjective counterpart - מנסה, משקר; and then many adjectives where the verb would go in another template, ארוך - האריך, שמן - השמין, גבוה - הגביה.

[TeribleT]

Hem lo mechadshim klum.

[MrsT637020]

What does the Hebrew mean to renew something?

[TeribleT]

Pealim has it as renew, innovate, modernise.
I've seen it used as refresh/ from new. Like "כל יום מחדש"