The following spelling rule explains that "likely" is spelled "likely" rather than "likly." (1

When the suffix ends with a consonant, keep the "e" on the main word.

When the suffix begins with a consonant, keep the "e" on the main word.

When the main word ends in "e," keep the "e" and add "ly."

O When the main words ends in a consonant then a vowel, keep the "e" and add "ly."

When the main words ends in "e," keep the "e" and add "ly."

Explanation:

When it comes to word spelling, several rules have to be considered. When it comes to words that ends in "e," you only need to add "ly." For example:

love + ly = lovely like + ly - likely complete + ly = completely definite + ly = definitely

However, there is an exemption to this rule. For example:

true = truly

In this case, you have to remove the letter "e" and add "ly."

So, this explains the answer.