Consonant cluster

A consonant cluster is a group of consonants in a word with no vowel(s) separating them. Very common in English, this phenomenon is particularly difficult for speakers of languages such as Spanish, Arabic and Japanese, where vowel/consonant or consonant/vowel follow each other quite strictly.

Consonant clusters can occur at the beginning of a word, in the middle, and/or at the end. Linking further hinders understanding for students.

Examples of clusters
Note: Don't confuse consonants with consonant letters. For example system /ˈsɪstəm/ begins with only one consonant and not 4, because "y" is a vowel in this case. See Decoding the letter Y.

Beginning
English words can have up to three consonants at the beginning of a word:
 * screw; split; sprain; strange; street;

Middle
English words can have four or even five consonants in the middle of a word. In these cases they will be in different syllables.
 * handspring /nd.spr/
 * abstract /b.str/
 * extra /k.str/
 * explain /k.spl/
 * instruct /n.str/
 * sightscreen /t.skr/
 * watchstrap /tʃ.str/ (/tʃ/ counts as only one consonant)

Ending
Although not very frequent, English words can have up to four consonants at the end of a word:
 * attempts /mpts/
 * glimpsed /mpst/
 * sixths /ksθs/
 * twelfths /lfθs/
 * thousandths /ndθs/