1, but not 2.
3, not 4. 5 - maybe. 6 is odd - watching what at 6:00?
1. Mom had to check the timer every 10 minutes.
2. Mom had to check the timer every 10th minute.
(Can we use both expressions?)
3. How about going at 6:00 at the art center.
4. How about coming at 6:00 at the art center.
5. How about arriving at 6:00 at the art center.
6. How about watching at 6:00 at the art center.
(Would you watch the ing forms? Are they grammatical from #3 to #6?)
2 answers
1. is correct.
5. and 6. are correct.
3. and 4. You need to change the preposition to "to."
5. and 6. are correct.
3. and 4. You need to change the preposition to "to."