Finite and non finite verbs

• Finite Verbs (sometimes called main verbs) are verb from suitable for use in predicates in that they carry inflections or other formal characteristics limiting their number (singular/plural), persons, and tense (past / present etc). Finite verbs can function on their own as the core of an independent sentence. 
• In English, as in most related languages, only verbs in certain moods are finite. These include:
• the indicative mood (expressing a state of affairs); e.g., “The bulldozer demolished the restaurant,” “The leaves were yellow and stiff.”
• the imperative mood (giving a command).
• the subjunctive mood (expressing something that might or might not be the state of affairs, depending on some other part of the sentence); nearly extinct in English.

Example

• I walked, they walk, and she walk = are finite verbs.

* (to) walk is an infinitive.

• I lived in Germany.

* ‘I’ is the subject. ‘lived’ describes what the subject did. ‘lived’ is a finite.

The finite verbs are highlighted in the following sentences:
The bear caught a salmon in the stream.
Who ate the pie?
Stop!

• A nonfinite verb form – such as a participle, infinitive, or gerund – is not limited by by time (see tense), person, and number. 
• Verb forms that are not finite include:
• the infinitive
• Participles (e.g., “The broken window…”, “The wheezing gentleman…”)
• gerunds and gerundives

• In linguistics, a non-finite verb (or a verbal) is a verb form that is not limited by a subject; and more generally, it is not fully inflected by categories that are marked inflectionally in language, such as tense, aspect, mood, number, gender, and person. As a result, a non-finite verb cannot generally serve as the main verb in an independent clause; rather, it heads a non-finite clause.
• By some accounts, a non-finite verb acts simultaneously as a verb and as another part of speech; it can take adverbs and certain kinds of verb arguments, producing a verbal phrase (i.e., non-finite clause), and this phrase then plays a different role — usually noun, adjective, or adverb — in a greater clause. This is the reason for the term verbal; non-finite verbs have traditionally been classified as verbal nouns, verbal adjectives, or verbal adverbs.
• English has three kinds of verbal: participles, which function as adjectives; gerunds, which function as nouns; and infinitives, which have noun-like, adjective-like, and adverb-like functions. Each of these is also used in various common constructs; for example, the past participle is used in forming the perfect aspect (to have done).