English grammar
I doubt (that)... / I'm not sure (that)...
Express doubt and uncertainty with I doubt / I'm not sure, without adding an extra negative.
From the scene I doubt she can cook
In short
After I doubt or I'm not sure, keep the sentence positive: I doubt it'll turn out well.
Your turn
Which one goes with I'm not sure (that) + clause?
Options: I doubt it'll turn out well. · I doubt it's too little. ✗ I doubt it isn't… · I'm not sure it's enough rice.
Show answer
I'm not sure (that) + clause → I'm not sure it's enough rice.
How it works
Doubt and not sure already carry the doubt, so the clause after them stays positive.
Your turn
Pick the word that fits the line.
I doubt (blank) too little. You're taking two kilos!
Options: it's not · it's · it isn't
Show answer
I doubt it's too little. You're taking two kilos!
Dudo que sea poco. ¡Llevas dos kilos!
Good to know
I doubt it'll turn out well, I'm not sure it's enough rice. The word that is often dropped.
Your turn
Pick the word that fits the line.
I'm not sure you (blank) that much rice, dear.
Options: need · don't need · won't need
Show answer
I'm not sure you need that much rice, dear.
No estoy segura de que necesites tanto arroz, cariño.
I doubt (that) + clause I doubt it'll turn out well.
Nuria
Thanks. I doubt it'll turn out well. I've never made paella.
Gracias. Dudo que me salga bien. Nunca he hecho paella.
Your turn
What fills the gap?
Thanks. (blank). I've never made paella.
Options: I'm not sure it's enough rice · I doubt it's too little. ✗ I doubt it isn't · I doubt it'll turn out well
Show answer
Nuria
Thanks. I doubt it'll turn out well. I've never made paella.
Gracias. Dudo que me salga bien. Nunca he hecho paella.
I'm not sure (that) + clause I'm not sure it's enough rice.
Nuria
Yes, but I'm not sure it's enough rice.
Sí, pero no estoy segura de que sea suficiente arroz.
Your turn
What fills the gap?
Yes, but (blank).
Options: I doubt it's too little. ✗ I doubt it isn't · I'm not sure it's enough rice · I doubt it'll turn out well
Show answer
Nuria
Yes, but I'm not sure it's enough rice.
Sí, pero no estoy segura de que sea suficiente arroz.
no extra negative I doubt it's too little. ✗ I doubt it isn't…
doubt + she'll I doubt she'll let you cook alone.
Your turn
What goes with I doubt she'll let you cook alone.?
Options: doubt + she'll · I doubt (that) + clause · I'm not sure (that) + clause
Show answer
I doubt she'll let you cook alone. → doubt + she'll
Common mistake
Not it isn't or it's not here. No extra negative needed.
Yes, but I'm not sure it's enough rice.
Sí, pero no estoy segura de que sea suficiente arroz.
Practise it in the story
Meet this rule inside a short animated scene. Answer as it plays, then say the lines yourself.
Practise free in the appSee all forms
| I doubt (that) + clause | I doubt it'll turn out well. |
|---|---|
| I'm not sure (that) + clause | I'm not sure it's enough rice. |
| no extra negative | I doubt it's too little. ✗ I doubt it isn't… |
| doubt + she'll | I doubt she'll let you cook alone. |
More lines from the story
- TomásI doubt it's too little. You're taking two kilos!Dudo que sea poco. ¡Llevas dos kilos!
- ElenaI'm not sure you need that much rice, dear.No estoy segura de que necesites tanto arroz, cariño.
- ElenaPaella? I doubt you'll make it better than me.¿Paella? Dudo que la hagas mejor que yo.
- TomásHere you go, the best rice in the whole market.Aquí tienes, el mejor arroz de todo el mercado.