How do you spell i's and t's like in dot your i's and t's?

Answer 1

How do you spell i's and t's like in dot your i's and [cross your] t's?

Simple. You may use double or single quotation marks as in:

Dot your "i"s and cross your "t"s.

OR

Dot your 'i's and cross your 't's.

In this particular case, you will notice that the use of the quotation marks help to avoid confusion of the present simple verb form "is" with the pluralising of the letter "i". Also, bear in mind that the use of the apostrophe for pluralising letters and numbers is, in fact, ungrammatical in prescribed grammar. Therefore, careful writers avoid such usage. Of course, you may use upper case letters where the information will not be misleading, for example,

There are 2 Ps in "Mississippi".

But you could also write

There are 2 PS in "Mississippi".