Because Hebrew is a phonetic language, there are fewer options for word construction. This means that changing one letter of a Hebrew word can change the entire meaning of the word. Here are some common mistakes and their meanings:

b’divreichem – in your words
b’divreihem – in their words

hane’emanim – that are believed
hane’emarim – that are said

tsiur – a drawing
tsur – a rock

Gad – Gad (one of the sons of Jacob)
dag – a fish

habanim – the children
habonim – the builders

hazeh – the this
haseh – the sheep

mah – what
meit – dead

sheloshim – thirty
shileishim – thirds