START and BEGIN accept BOTH forms with no difference in meaning in most contexts: "She started working" = "She started to work." However, with cognitive/stative verbs (understand, realize, feel, know) TO is preferred: "I began to understand" (not "began understanding"). And when START/BEGIN is in the CONTINUOUS form (-ING), the infinitive is preferred for the following action: "She is starting to learn" (not "is starting learning").
START/BEGIN + -ING: accepted in almost all contexts, with a slight emphasis on the PROCESS or CONTINUITY of the action beginning. "She started working on the project in January." "They began implementing the changes immediately." "It started raining at noon." WHEN -ING IS MORE NATURAL: (1) When emphasizing duration or process. (2) When the initiated action is a habit or continuous task. (3) In narratives and descriptions where there is already a series of actions. STATIVE/COGNITIVE VERBS — EXCEPTION: with verbs expressing mental states (understand, realize, feel, see, know), START/BEGIN + -ING feels awkward: "He started realizing his mistake" = sounds odd. "He started to realize his mistake" = correct and natural. Reason: stative verbs do not form natural gerunds in this context.
The organization started implementing the new data governance policy across all divisions in the third quarter, a process that is expected to take approximately eighteen months to complete at the pace currently planned.
Once the board approved the revised budget, the operations team began recruiting for the three new positions that had previously been frozen, with the intention of having all roles filled before the start of the next financial year.
As the workshop progressed, participants started contributing more freely to the discussion and offering examples from their own professional experience, which significantly enriched the quality of the collective analysis.
START/BEGIN + TO + INFINITIVE: semantic equivalent in most contexts, with slight emphasis on the STARTING POINT of the action. "She started to work on the project." WHEN TO + INFINITIVE IS PREFERRED OR REQUIRED: (1) WHEN START/BEGIN ARE IN CONTINUOUS FORM: "She is starting to work on it" = correct. "She is starting working on it" = sounds awkward (two -ING forms in a row). Rule: when START/BEGIN are in -ING, the following complement = TO + infinitive. (2) WITH COGNITIVE/STATIVE VERBS: "I began to understand the implications" = correct. "I began understanding..." = sounds odd. (3) IN FORMAL WRITTEN ENGLISH: TO + infinitive often sounds slightly more formal. (4) SUBTLE PERSPECTIVE DIFFERENCE: START -ING = process underway. START TO = the starting point of the process (but this difference is very subtle and not always perceived). In practice: in 90% of contexts, they are interchangeable.
After attending the third briefing on the proposed merger, several board members began to realize that the due diligence process had not been as comprehensive as initially reported, raising concerns about the robustness of the transaction's underlying rationale.
The project management office is starting to develop a standardized framework for cross-departmental collaboration, drawing on the lessons learned from three major initiatives that were completed during the previous financial year.
Following the publication of the independent review, the sector began to understand the full extent of the systemic risks that had been accumulating over the preceding decade and which the previous regulatory framework had failed to adequately address.
Common mistake
THE TWO CONTEXTS WHERE THE CHOICE MATTERS: (1) START/BEGIN IN CONTINUOUS FORM: "She is starting working on it" = sounds wrong. "She is starting TO WORK on it" = correct. Rule: -ING + -ING = avoid. When START/BEGIN is already in -ING, the complement = TO. (2) COGNITIVE/STATIVE VERBS: "He started understanding" = sounds odd. "He started TO UNDERSTAND" = correct. Key verbs: understand, realize, feel, see, know, think, believe. DIFFERENCE FROM STOP/REMEMBER/FORGET: unlike STOP, REMEMBER, and FORGET (where the -ING/TO change radically changes the meaning), with START and BEGIN -ING and TO are almost always interchangeable. There is no same drastic meaning change as in "He stopped smoking" vs "He stopped to smoke."
Trick to remember it
THE TWO-CASE RULE: (1) START/BEGIN in -ING (continuous) = the next verb MUST be TO: "is starting TO work / was beginning TO realize." (2) Cognitive verb follows (understand, realize, feel, know) = TO is preferred. IN EVERYTHING ELSE: -ING and TO are equivalent with START and BEGIN. Unlike STOP/REMEMBER, there is no meaning change. "She started working" = "She started to work." Both correct in 90% of contexts.
Quick rule
START/BEGIN + -ING = same as START/BEGIN + TO in almost all contexts. EXCEPTIONS: (1) START/BEGIN in continuous (-ING) = complement uses TO, not -ING: "is starting TO work" (not "is starting working"). (2) Cognitive/stative verbs = TO: "started TO realize / began TO understand" (not "started realizing," though possible, sounds odd).
Did you know?
The START/BEGIN pair is the best example of the linguistic phenomenon known as "complementation symmetry" — the ability of a verb to accept both gerund and infinitive without change of meaning. Linguists have studied why some English verbs allow this double complementation (START, BEGIN, CONTINUE, INTEND) while others do NOT (STOP, REMEMBER, FORGET — where the change has semantic consequences). The most accepted theory is that double complementation arises when the temporal aspect of the action is so natural and expected that grammar does not need to distinguish between the process (gerund) and the goal/start (infinitive). With STOP, however, the process/goal distinction IS semantically relevant (stopping doing X vs stopping in order to do X are two different things), so the language maintains the morphological distinction. This contrast illustrates how grammatical form (the -ING suffix vs the TO particle) can encode important semantic distinctions... or not, depending on communicative need.
Exercise 1 · Pick the right one
Following the regulatory update, companies across the sector began _____ their compliance frameworks to align with the new requirements, with most organizations targeting full alignment before the end of the transitional period.
Exercise 2 · Pick the right one
Several weeks into the restructuring process, the workforce was starting _____ the full implications of the changes that had been announced, and morale across all departments had deteriorated significantly.
Exercise 3 · Form the word
START/BEGIN + -ING = same as START/BEGIN + TO in almost all contexts. EXCEPTIONS: (1) START/BEGIN in continuous (-ING) = complement uses TO, not -ING: "is starting TO work" (not "is starting working"). (2) Cognitive/stative verbs = TO: "started TO realize / began TO understand" (not "started realizing," though possible, sounds odd).
THE TWO CONTEXTS WHERE THE CHOICE MATTERS: (1) START/BEGIN IN CONTINUOUS FORM: "She is starting working on it" = sounds wrong. "She is starting TO WORK on it" = correct. Rule: -ING + -ING = avoid. When START/BEGIN is already in -ING, the complement = TO. (2) COGNITIVE/STATIVE VERBS: "He started understanding" = sounds odd. "He started TO UNDERSTAND" = correct. Key verbs: understand, realize, feel, see, know, think, believe. DIFFERENCE FROM STOP/REMEMBER/FORGET: unlike STOP, REMEMBER, and FORGET (where the -ING/TO change radically changes the meaning), with START and BEGIN -ING and TO are almost always interchangeable. There is no same drastic meaning change as in "He stopped smoking" vs "He stopped to smoke."
THE TWO-CASE RULE: (1) START/BEGIN in -ING (continuous) = the next verb MUST be TO: "is starting TO work / was beginning TO realize." (2) Cognitive verb follows (understand, realize, feel, know) = TO is preferred. IN EVERYTHING ELSE: -ING and TO are equivalent with START and BEGIN. Unlike STOP/REMEMBER, there is no meaning change. "She started working" = "She started to work." Both correct in 90% of contexts.
Bryan López
Founder of SpeakUP Academy