The term "colonial army" is a noun. The plural form would be colonial armies.
Strictly, 'the army lost its first battle', or acceptably, 'the army lost their first battle'. The singular is traditionally used about the enemy, though plural is also used, equally correctly.
No it is not. The word "these" refers to a plural noun whereas the word "family" is the single form of a noun. You can either say, "These are the members of my family" or "This is my family." Unfortunately many people, including MPs and TV presenters do not seem to know this grammatical rule. We hear such as, "The army are..;" when it should be "The army is..." Only one single army is being spoken about. Otherwise they should say, "Our soldiers are...".
Plural
The plural noun of general is generals. Generals is a regular plural noun.
The plural of army is armies.
If you are asking what the plural noun of the word 'army' is, then it's armies.
The plural form for the noun army is armies. The plural possessive form is armies'.
The army is singular.
If you mean "Army" then the plural is "Armies".
The plural of army is armies. As in "the two armies marched against each other".
armies
The word army is a singular noun; armies is the plural form.
The plural for for the noun army is armies. Example: The armies fought bravely.
The plural form for the noun army is armies.To form the plural for words ending in y preceded by a consonant:change the y into ie and add s.
armies
The noun armies' is the plural possessive for the singular army.