How to know when to use the word To, or Too? This is a common question, but don't worry, here is an easy way to know the difference.
Too is about an amount, quantity or level
Think about your sentence. Will you be using the word to describe something to do about an amount, quantity or level? If so, you'll want to use "Too". Here are some examples where Too is used correctly:
I had too many letters arrive in my mailbox and ran out of space
She had too few eggs in the refrigerator for the recipe
He was dressed far too formally for the occasion
To describes a relationship to something
If you are planning to use the word to describe where someone or something went or is going to do, then you most likely want to use "To". Here are some examples where To is used correctly:
I went to the bank
He handed the pen to the customer
She could not believe he said that to her
I find it easiest if I ask myself "did someone or something something, even just words, go from one spot to another?" and "Is something or someone about to cause something to happen in the future?" If the answer to either is yes, then you'll want to use "to".
When both words need to be used in a sentence
You may come across occasions where both words are to be used within the same same sentence. The same rules above apply; when talking about a quantity or amount you should use "Too". When talking about something that goes from one spot to another or about something that could happen in the future, use "To". Here are some examples where Too and To are used correctly in the same sentence:
He had too many things he wanted to bring on the trip
She went to the gala in an outfit that was too short for modesty
The weather was too rainy for them to go to the beach
If you are really stuck
First of all, go with the guidelines above. Do your best to figure out which of the 2 words you need. Then, check your results with a free online grammar checker. Most reputable ones do an excellent job of knowing the difference between to and too. The ones we recommend for this are:
At the time of writing, the tools I mentioned here are all free to use and will alert you to the difference between to and too. No account is needed for use.