Translation of "once I" into Spanish

Phrases similar to "once I" with translations into Spanish

• I run once a week
  corro una vez a la semana
• I once
  una vez yo
• never once did I ask them for help
  ni una sola vez les pedí ayuda
• I can't do two things at once at the same time
  no puedo hacer dos cosas al mismo tiempo
• I went there just once
  fui solo una vez
• I write home once a week
  escribo a casa una vez por semana