What's the difference in meaning between "hold on", "hold on to", and "hold up?"
Answer from a Native speaker
"Hold on" can either mean to physically hold something, or it can mean to "wait" or "wait a second." To "hold on to [something]" means to hold something and not let go, either physically or metaphorically, or to keep something for someone for an amount of time. "Hold up" means to either hold something "up" at a particular height, or it can mean to delay or block something from moving or progressing, or it can also mean to "wait" or "stop." Ex: Can you hold on to my jacket for me until I come back from vacation? Ex: Hold on! I forgot my bag. I'll go get it quickly. Ex: Hold on and don't let go. = Hold on to the rail and don't let go. Ex: Can you hold up the painting for me? Ex: Sorry I'm late. I was held up by the traffic.