Я хочу изменить план.

I

Breakdown of Я хочу изменить план.

• хотеть: to want
• план: the plan
• изменить: to change

Questions & Answers about Я хочу изменить план.

Why isn’t there a word like “the” or “a” before план?

Russian doesn’t use articles at all.
So план on its own can mean:

• the plan
• a plan
• my/our plan (if clear from context)

Context (what was said before, the situation, intonation) tells you whether план is definite or indefinite. Grammatically it is just план, without any extra word.

How do I know that план is in the accusative case if it just looks like the dictionary form?

In this sentence план is the direct object of изменить, so it must be in the accusative case.

Masculine inanimate nouns (like план) have the same form in:

• Nominative singular (dictionary form): план
• Accusative singular: план

So the form doesn’t change, but the function does:

• План готов. – план is the subject (nominative).
• Я хочу изменить план. – план is the object (accusative).

Why is изменить in the infinitive form and not conjugated like the main verb?