An important rule that applies to consonant blends is that the individual consonants within a blend cannot be separated by vowels. Another rule is that each letter is pronounced individually, but quickly.

Consonant blends may consist of either two or three consonants appearing together within a word. Since there is no vowel separation between each consonant, the sound of each letter is produced quickly. At the same time, each letter sound is distinctive and combines or blends with other letter sounds in a smooth manner. Examples of two-consonant blends include “sp” in “spare,” “bl” in “blacken,” “pr” in “progress” and “st” in “poorest.” Many three-consonant blends begin within the letter “s.” Some examples are “str” in “straight,” “scr” in “scrub” and “spr” in “sprightly.”

Consonant blends can appear at the beginnings or the ends of words. Initial consonant blends or beginning blends include "s" blends such as “sn,” “sp” and “sm,” "l" blends such as “pl,” and "r" blends such as “dr” and “fr.” Final consonant blends, also known as end blends, include "s" blends such as “sp” and “st,” "l" blends such as “lt” and “ld,” and "n" blends such as “nd.” Other commonly used end blends are “rt” and “mp.”

Consonant digraphs look similar to consonant blends, but they differ in one crucial aspect. In digraphs, the consonants placed together do not retain their original distinctive sounds but produce entirely new sounds. Common examples of digraphs include “ch” in “character,” “sh” in “sharpen” and “ph” in “photographer.”