So begins Fox in Socks, by Dr Seuss (Theodore Seuss Geisel), a series of increasingly intricate tongue-twisters. Along the way, whether Seuss intended it to or not, it illustrates many points of English pronunciation and spelling.
Each of the words has four phonemes (distinct sounds) in pronunciation, represented by three, four or five letters in spelling, so immediately there is not a direct correspondence between sound and spelling. Each of the words starts with one consonant phoneme /f/, /s/, /b/ and /n/. The first three are represented by one letter, but the last is represented by two letters kn – the k is silent. It used to be pronounced but now it isn’t (long story). (In fact, the k is silent in all English words starting with kn.)
At church this morning (Easter Day), the first reading was from The Axe of the Apostles – sorry, The Acts of the Apostles. English allows final consonant clusters of two, three and four consonants, but almost everyone simplifies these in some way (natives speakers probably only the three- or four-consonant clusters; second language speakers/learners even two-syllable clusters. I have even noticed that some students tend to drop any consonant at the end of a word.). Acts = /ækts/. I suspect that most native English speakers reduce to this to /æks/ = axe most of the time, even in the very formal setting of a major historic parish church on Easter Day. (The reader was otherwise impeccably enounced.) Many second language speakers/learners, on the other hand, drop the s, especially if plural marking is optional or non-existent in their language and/or it does not allow many/any final consonant clusters and/or /s/ is not permitted at the end of those which are allowed.