Quick answer: Onto (one word) is a preposition showing movement to a position on top of something: The cat jumped onto the table. On to (two words) occurs when "on" is part of a phrasal verb and "to" is a separate preposition: Let's move on to the next topic. Check whether "on" pairs with the verb before it. For a fuller definition, see the Cambridge Dictionary entry for ‘onto’.
Comparison Table
| Word | Part of Speech | Meaning | Example |
|---|---|---|---|
| onto | preposition | movement to a position on top of or onto a surface | He climbed onto the roof to fix the aerial. |
| on to | adverb "on" + preposition "to" | "on" completes a phrasal verb; "to" introduces what follows | Let's move on to the next question. |
Using Onto
Onto is a single preposition describing movement to a position on top of a surface or object.
The children climbed onto the climbing frame.
She stepped onto the stage to accept the award.
The dog jumped onto the sofa the moment we left.
Water spilled onto the kitchen floor.
Using On To
On to appears when "on" is part of a two-word verb (move on, hold on, log on, hang on) and "to" introduces a separate object or purpose.
Let's move on to the next item on the agenda.
She held on to the rope as she crossed the bridge.
Please log on to the portal before nine o'clock.
Hang on to your ticket — you'll need it later.
Memory Trick
Ask yourself: does "on" belong with the verb right before it as its own phrasal verb (move on, hold on, log on)? If yes, keep "on" and "to" apart: "on to". If the phrase is simply about movement to a surface, join them: "onto" (think: "on-to the top" = movement to a position on top).
Common Mistakes
✗ Let's move onto the next chapter.
✓ Let's move on to the next chapter.
"Move on" is the phrasal verb meaning to progress; "to the next chapter" tells where you're progressing.
✗ The cat leapt on to the windowsill in one jump.
✓ The cat leapt onto the windowsill in one jump.
Tips to Avoid Confusion
- If the sentence is about physical movement to a position on top of something, use one word: onto.
- If "on" is part of a phrasal verb (move on, hold on, log on, hang on) and "to" starts a new idea, keep them separate: on to.
- Try pausing briefly between "on" and "to" — if it still sounds natural, it's likely the two-word form.
- When in doubt with abstract or figurative senses (progressing, continuing), "on to" is usually the safer two-word choice.
For more on related grammar, see prepositions. Also confusing: Afraid vs Frightened, Alone vs Lonely, Angry vs Furious. Browse all confusing word pairs →
Quick Check: Onto or On To?
4 fill-in-the-blank questions — choose the correct word for each sentence.
1. “The gymnast landed ___ the mat perfectly.”
2. “Now let's move ___ the second part of the lesson.”
3. “Hold ___ your hat — it's very windy today.”
4. “She climbed ___ the ladder to reach the top shelf.”
Frequently Asked Questions
What is the difference between onto and on to?
Onto (one word) is a preposition showing movement to a position on top of something: "The cat jumped onto the table." On to (two words) occurs when 'on' is part of a phrasal verb and 'to' is a separate preposition: "Let's move on to the next topic", "She held on to the railing."
Why are onto and on to so often confused?
They sound the same and both involve the concept of 'on' plus 'to', so writers often don't stop to check whether 'on' actually belongs with the verb before it as a phrasal verb.
How can I test whether I need onto or on to?
Check whether 'on' pairs with the verb before it as a phrasal verb, like 'move on', 'hold on', or 'log on'. If so, keep 'on' and 'to' separate: 'on to'. If the phrase simply describes movement to a surface, join them: 'onto'.
Is 'move onto' or 'move on to' correct for changing topics?
'Move on to' (two words) is correct here, because 'move on' is the phrasal verb meaning to progress, and 'to' introduces the next topic: "Let's move on to question three." 'Move onto' with one word would only apply to physical movement onto a surface.
Does 'hold on to' need onto or on to?
It needs 'on to' (two words), since 'hold on' is the phrasal verb meaning to grip firmly, and 'to' introduces what is being held: "Hold on to the railing as you climb the stairs."
Can onto describe more than physical position?
Yes, informally: "I'm onto something big," meaning you've discovered or figured out something important. This figurative use still treats 'onto' as a single preposition.
Is 'log on to' or 'log onto' more correct?
'Log on to' (two words) reflects the precise phrasal-verb structure ('log on' + 'to'), similar to 'log in to'. 'Log onto' is common informally, but careful writing keeps them as three separate words: log on to.
Can onto be used for stepping onto a vehicle?
Yes: "Passengers stepped onto the train platform," or "She climbed onto the bus." This is a straightforward physical-movement use of the single-word preposition.
Does British and American English differ on onto vs on to?
The grammatical distinction is the same in both varieties, though some British style guides are historically more cautious about using 'onto' at all, preferring 'on to' even for physical movement in very formal writing. Modern usage in both varieties generally follows the phrasal-verb test above.
How can I remember onto vs on to?
If 'on' is part of a phrasal verb with the word before it (move on, hold on, log on) and 'to' introduces something new, keep them as two words: 'on to'. If the phrase is simply about movement to a surface, join them: 'onto'.