Evidence-based answer · Last updated · How it’s made
Research on EFL writing shows that nonfinite verb forms (infinitives, -ing/participle clauses, and other verb forms without tense marking) are used with increasing frequency and sophistication as learners' proficiency grows, but they remain a persistent source of difficulty — especially for learners whose native language does not mark this distinction grammatically, like Chinese speakers. Nonfinite structures also behave differently depending on genre: they're associated more with informal, conversational-style writing, and EFL learners often fail to adjust their use of them when switching between formal and informal writing tasks.
Answered for language learning in general. No specific language was set for this question, so the findings are drawn from general second-language research rather than one language’s literature.
Chinese EFL learners, whose native language has no grammatical marking that distinguishes finite from nonfinite verbs, show clear evidence of transferring patterns from Chinese into English: they both use unmarked "bare" verb forms where English requires nonfinite marking and over-add finite-like markings onto nonfinite verbs.1
In plain terms
As Chinese learners' English proficiency improves, their errors placing nonfinite verbs in the wrong sentence position (syntactic errors) drop sharply, but errors in the actual word form used (morphological errors) persist even at higher levels.1
Higher-proficiency learners generally use more subordinate clauses (clauses embedded inside a larger sentence) overall, and their use of nonfinite subordinate structures — particularly complement clauses (clauses that complete the meaning of a verb, like "decided to leave") — increases specifically as proficiency rises, while other clause types increase regardless of whether they're finite or nonfinite.4
Nonfinite adverbial and verb-complement clauses are more typical of casual, spoken-like writing, while finite noun-complement clauses and phrasal noun modifiers are more typical of academic writing.6
EFL learners generally fail to adjust their use of nonfinite adverbial and verb-complement clauses when moving between academic and colloquial writing tasks, even though these features are known to differ by register in native-like writing; this lack of adjustment did not improve with higher English proficiency.6
In plain terms
Korean college freshmen used to-infinitives (structures like "to go" or "to see") with a fairly low overall error rate, suggesting fairly solid general command of this nonfinite form, but the errors that did occur mostly involved not knowing which specific pattern a given verb requires afterward.3
In plain terms
Among several grammatical features studied in EFL argumentative essays, nonfinite relative clauses (participle-based modifiers like "the book written by... " or "the man standing there") showed the strongest and most consistent link to essay quality, with higher-rated essays using them significantly more than lower-rated ones.7
In a multi-semester study tracking two learners, the frequency and variety of nonfinite verb structures (along with other complexity features) tended to increase over time, though individual learners diverged from each other more as time went on, showing this growth isn't uniform across learners.2
A close, longitudinal case study of one adult EFL learner's development of nonfinite adverbial clauses (structures like "before leaving" or "without knowing") found that this development did not progress smoothly, but went through abrupt shifts where old patterns broke down and new ones emerged, consistent with language development being a dynamic, non-linear process rather than steady linear growth.5
Even in native English, the rules for nonfinite complementation clauses after certain verbs (such as "prevent" and "stop," as in "prevented it from happening" versus "prevented it happening") have shifted over the past two centuries, meaning that this part of English grammar is a genuinely moving target that EFL materials and instruction must keep up with.8
Studies of a child learning German as a second language found that nonfinite verb markers appeared in the correct grammatical positions, while unmarked "bare" verb forms appeared in finite-verb positions, suggesting learners' errors follow systematic patterns rather than being random.9
Now pick something to do it with
Each of these opens an overview of the apps, courses and immersion material worth a look for that — filtered to exactly what the advice above points you at:
Or see the full resource list