The plural of engine is engines.
The plural form for the singular noun engineer is engineers.
engines
"engines"
vehicles <><><><><> It depends on whether you want plural or possessive. My vehicle's engine is bad. Our vehicles are bad. You can also have plural possessive: vehicles'
The plural of "she" is "they", so the plural of "she had" is "they had".
The plural of 'this' is 'these' and the plural of 'that' is 'those'.
Isthmi is plural. There are actually two plural forms. I will list them from singular to plural. Isthmus - Singular Isthmi - Plural Isthmuses - Plural
The plural of rose is roses. The plural possessive is roses'.
applied is does not have a plural but is apply it does have a plural.
Knights is a plural. It is the plural for knight.
The plural form of can is cans.
The plural is a regular plural, attics.