Tomio,

Yes, all are natural; all are grammatical; all are acceptable.

PED

-----Original Message-----
From: SIRAISI Tomio <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Tuesday, November 09, 1999 5:19 PM
Subject: get/grow/become/turn dark


>Dear everyone
>
>Are the following expressions natural?
>1. It is getting dark.
>2. It is growing dark.
>3. It is becoming dark.
>4. It is turning dark.
>
>I suppose 1 and 2 are all right but I wonder whether 3 and 4 are natural.
>
>I have only two examples of 'become dark', and as for 'turn dark' I have
>none.
>
>(a) A little over an hour passed.  It became dark in Phil's prison,
>  but he had no means of lighting the gas.  There was a small bed in
>  the room, and he made up his mind that he must sleep there.
>                                   -- Horatio Alger, The Errand Boy
>(b) Presently the sun set and it became dark, whereon the pair retired
>  into the inner part of the cave and went to bed.
>                                   -- Homer-Butler, The Odyssey
>
>Thanks in advance.
>
>SIRAISI Tomiio