📄️ Introduction
This Section, and Sections 9–10, deal with verb forms like (to) write (infinitive), speaking (\-ing form) and seen (past participle). These forms do not themselves have any time reference (unlike for example writes or spoke), and grammarians call them ‘non-finite’. However, they can be used together with auxiliary verbs to form tenses: e.g. will write, *is speaking, *has **seen (see here). They also have various other uses which are explained in Sections 8–10.
📄️ Infinitives: introduction
Infinitives have many functions. An infinitive can be used, for example, after do or a modal auxiliary verb as part of a verb phrase.
📄️ Infinitives: forms
Infinitives are most often used with to (e.g. to** go*, to start). For infinitives without to, (see here). Besides simple infinitives, there are also progressive infinitives (e.g. (to) be writing), perfect infinitives (e.g. (to) have written), and passive infinitives (e.g. (to) be written*).
📄️ Use of perfect infinitives: *glad to have left*
Perfect or past meaning
📄️ Infinitives without to: *I saw you come in.*
We usually use to with infinitives (e.g. I want to know). But we use the infinitive without to (sometimes called the ‘bare infinitive’) in some cases.
📄️ Infinitive as subject or complement
Subject: To practise is important. / It’s important to practise.
📄️ -ing forms: introduction
‘participles’ and ‘gerunds’
📄️ -ing form as subject, object or complement
Smoking is bad for you.
📄️ Infinitive or -ing form?
Infinitives and \-ing forms are often used in similar ways. For instance, they can follow certain verbs, adjectives or nouns (Infinitives, -ing forms and past participles after nouns, verbs, etc). Compare:
📄️ Participles: -ing and -ed forms used like adjectives
Names