The length and quality of the vowels are different, and these are very significant in English but not in Spanish.

/ɪ/ vs. /iː/

Short /ɪ/Long /iː/
shipsheep
bitbeat
liveleave
sitseat
fillfeel
lidlead
slipsleep
gringreen
pickpeak
chickcheek

/æ/ vs. /ɑː/

/æ/ (as in “cat”)/ɑː/ (as in “cart”)
catcart
batbar
hatheart
matmart
patpart
capcarp
taptarp
backbark
sacksock
lacklark

/ʌ/ vs. /ɑ/

/ʌ/ (as in “cut”)/ɑ/ (as in “cot”)
cutcot
lucklock
duckdock
shutshot
cupcop
mudmod
budbod
nutknot
sucksock
rutrot