Onto vs. On To: What's the Difference?
Quick Answer
onto = preposition — movement to a position on a surface
on to = "on" (part of a phrasal verb) + separate "to" (move on to, hold on to)
Explanation
ONTO (one word)
Preposition: movement to a surface/position
"The dog jumped onto the bed."
"She climbed onto the roof."
ON TO (two words)
"On" is part of a phrasal verb + "to"
"Let's move on to the next item." (move on)
"Hold on to your hat." (hold on)
Quick test: Remove "to" — does the remaining phrase still make sense as a verb (move on, hold on, log on)? Write on to. Otherwise, if it's about physical movement onto a surface, write onto.
Examples
Common Mistakes
Incorrect: Hold onto your tickets until you reach the gate.
Correct: Hold on to your tickets until you reach the gate. (hold on + to)
Incorrect: The cat leaped on to the windowsill.
Correct: The cat leaped onto the windowsill. (movement to a surface)
Practice
Choose the correct form:
"The kids climbed _____ the fence, then we moved _____ the next activity."