Here are some things to consider:
* General rules: We usually double consonants when a single vowel sound is followed by a consonant, and the word ends in a single consonant. Examples: "stop", "hop", "run". However, this doesn't apply to every single consonant.
* Exceptions: There are many exceptions to these rules, and some consonants are just less likely to be doubled. For example, "x" is rarely doubled, "w" is usually not doubled, and "h" is never doubled.
* Specific words: Sometimes, the spelling of a word is just an exception, and we can't easily apply the rules. For instance, "have" and "give" are both exceptions to the rule about doubling consonants.
Instead of trying to find 7 consonants you never double, it might be more helpful to learn the general rules about doubling consonants and then learn the exceptions as you come across them.
Let me know if you'd like to learn more about the rules for doubling consonants!