What's the difference between certain and sometimes?

Certain


Definition:

  • (a.) Assured in mind; having no doubts; free from suspicions concerning.
  • (a.) Determined; resolved; -- used with an infinitive.
  • (a.) Not to be doubted or denied; established as a fact.
  • (a.) Actually existing; sure to happen; inevitable.
  • (a.) Unfailing; infallible.
  • (a.) Fixed or stated; regular; determinate.
  • (a.) Not specifically named; indeterminate; indefinite; one or some; -- sometimes used independenty as a noun, and meaning certain persons.
  • (n.) Certainty.
  • (n.) A certain number or quantity.
  • (adv.) Certainly.

Example Sentences:

  • (1) One hour after direct mechanical cardiomassage (DMCM) a moderately pronounced edema of the intercellular spaces in the basal compartment of the seminiferous epithelium, normal content of lactate and succinate dehydrogenases, and a certain decrease in the activity of glucose-6-phosphate dehydrogenases and NAD- and NADP-diaphorases were noted.
  • (2) Work on humoral responses has focused on lysozyme, the hemagglutinins (especially in the oyster), and the clearance of certain antigens.
  • (3) Stress is laid on certain principles of diagnostic research in the event of extra-suprarenal pheochromocytomas.
  • (4) As a group, the three mammalian proteins resemble bovine serum conglutinin and behave as lectins with rather broad sugar specificities directed at certain non-reducing terminal N-acetylglucosamine, mannose, glucose and fucose residues, but with subtle differences in fine specificities.
  • (5) A segment of vas deferens was transplanted to the contralateral deferens with the intention of improving treatment for certain cases of infertility caused by obstruction.
  • (6) hypoglossal nucleus), whereas in other areas the angiotensinogen gene was expressed only in a certain population of glial cells.
  • (7) The following conclusions emerge: (i) when the 3' or the 3' penultimate base of the oligonucleotide mismatched an allele, no amplification product could be detected; (ii) when the mismatches were 3 and 4 bases from the 3' end of the primer, differential amplification was still observed, but only at certain concentrations of magnesium chloride; (iii) the mismatched allele can be detected in the presence of a 40-fold excess of the matched allele; (iv) primers as short as 13 nucleotides were effective; and (v) the specificity of the amplification could be overwhelmed by greatly increasing the concentration of target DNA.
  • (8) Certainly, Saunders did not land a single blow that threatened to stop his opponent, although he took quite a few himself that threatened his titles in the final few rounds.
  • (9) We present a mathematical model that is suitable to reconcile this apparent contradiction in the interpretation of the epidemiological data: the observed parallel time series for the spread of AIDS in groups with different risk of infection can be realized by computer simulation, if one assumes that the outbreak of full-blown AIDS only occurs if HIV and a certain infectious coagent (cofactor) CO are present.
  • (10) HDAra-C in combination with anthracyclines is now considered to be a treatment which may afford some hope of a cure in a certain percentage of cases of adult acute non-lymphocytic leukemia.
  • (11) These results suggest that a certain minimum level of expression of c-myc is required for the maintenance of ras transformation in NIH 3T3 cells.
  • (12) This "paradox of redistribution" was certainly observable in Britain, where Welfare retained its status as one of the 20th century's most exalted creations, even while those claiming benefits were treated with ever greater contempt.
  • (13) In certain cases, the effects of these substances are enhanced, in others, they are inhibited by compounds that were isolated from natural sources or prepared by chemical synthesis.
  • (14) Accumulating evidence indicates that for most tumors, the switch to the angiogenic phenotype depends upon the outcome of a balance between angiogenic stimulators and angiogenic inhibitors, both of which may be produced by tumor cells and perhaps by certain host cells.
  • (15) The findings indicate that these spaces were lined by a lipid monolayer which formed bilayered lamellae under certain conditions.
  • (16) Positive feedback effects on serum gonadotrophins in castrates were observed following injection of certain doses of some steroids.
  • (17) Hence, presence of IgG rheumatoid factor correlated positively with the presence of rheumatoid disease, and evidence was established that certain features of rheumatoid inflammation occur in dental periapical lesions of many patients with rheumatoid disease.
  • (18) The typology developed in two previous surveys of illicit heroin products is applicable to many of the samples studied in this work, although significant changes have occurred in the chemical profile of illicit heroin products from certain geographical regions.
  • (19) The presence of an inverse correlation between certain tryptophan metabolites, shown previously to be bladder carcinogens, and the N-nitrosamine content, especially after loading, was interpreted in view of the possible conversion of some tryptophan metabolites into N-nitrosamines either under endovesical conditions or during the execution of the colorimetric determination of these compounds.
  • (20) An electrogenic sodium-potassium pump appears to contribute materially to the steady-state potential and to certain of the transient potential responses of vascular smooth muscle.

Sometimes


Definition:

  • (adv.) Formerly; sometime.
  • (adv.) At times; at intervals; now and then;occasionally.
  • (a.) Former; sometime.

Example Sentences:

  • (1) Cor triatriatum (CT) is a rare congenital defect, surgically correctable, and sometimes difficult to diagnose by cardiac catheterization.
  • (2) The cause has been innumerable "VIP movements", as journeys undertaken by those considered important enough for all other traffic to be held up, sometimes for hours, are described in South Asian bureaucratic speak.
  • (3) In in vitro preparations GABA (10(-7) - 10(-3) M) elicited a dose-dependent relaxation; a decrease in the spontaneous contractions was sometimes observed.
  • (4) In a poll before the debate, 48% predicted that Merkel, who will become Europe's longest serving leader if re-elected on 22 September, would emerge as the winner of the US-style debate, while 26% favoured Steinbruck, a former finance minister who is known for his quick-wit and rhetorical skills, but sometimes comes across as arrogant.
  • (5) Neutral sucrose density sedimentation patterns indicate that neutron-induced double strand-breaks sometimes occur in clusters of more than 100 in the same phage and that the effeciency with which double strand-breaks form is about 50 times that of gamma-induced double strand-breaks.
  • (6) The advantages of the incision through the pars plana ciliaris are (1) easier approach to the vitreous cavity, (2) preservation of the crystalline lens and an intact iris, and (3) circumvention of the corneal and chamber angle complications sometimes associated with the transcorneal approach.
  • (7) All the same, it's hard to approach the school, which charges nearly £28,000 for boarders and nearly £19,000 for day girls and is sometimes called "the girls' Eton", without a few prejudices.
  • (8) Eleven had hematological disorders, and 12 received steroids (sometimes with immunosuppressive or cytotoxic drugs).
  • (9) But we sent out reconnoitres in the morning; we send out a team in advance and they get halfway down the road, maybe a quarter of the way down the road, sometimes three-quarters of the way down the road – we tried this three days in a row – and then the shelling starts and while I can’t point the finger at who starts the shelling, we get the absolute assurances from the Ukraine government that it’s not them.” Flags on all Australian government buildings will be flown at half-mast on Thursday, and an interdenominational memorial service will be held at St Patrick’s cathedral in Melbourne from 10.30am.
  • (10) Alveoli underlying the plasma membrane sometimes contain binding sites, particularly on their outer membranes.
  • (11) These results provide further data which counter the sometimes extreme advocates of the view that compulsory admission and treatment of patients with psychiatric illness is never acceptable.
  • (12) They have informed, advocated and sometimes goaded participants in a way that will be entirely familiar to people in Europe.
  • (13) The minimum contraction produced by the threshold current involved usually three or four, sometimes two, sarcomers on both sides of the injecting pipette but contraction involving only one sarcomere was not observered.
  • (14) Vascular disturbances may develop very early, sometimes in the first month after manifestation of the disease.
  • (15) A few chromosomes show only telomeric staining in one arm or sometimes in both arms.
  • (16) In the midst of all the newspaper headlines and vigils you can sometimes lose sight of the man who was on death row.
  • (17) Rayburn, who was also told by his jobcentre he would lose his benefits if he did not work without pay, said he spent almost two months stacking and cleaning shelves and sometimes doing night shifts.
  • (18) Although studies of the effect of manipulating sensory systems during development are sometimes difficult to interpret (e.g.
  • (19) 99mTc-PMT scintigraphy is useful in connection with 99mTc-colloid scan and sometimes with 67Ga-citrate in the diagnosis of intrahepatic masses originating from hepatocytes.
  • (20) Sometimes it can seem as if the history of the City is the history of its crises and disasters, from the banking crisis of 1825 (which saw undercapitalised banks collapse – perhaps the closest historic parallel to the contemporary credit crunch), through the Spanish panic of 1835, the railway bust of 1837, the crash of Overend Gurney, the Kaffir boom, the Westralian boom, the Marconi scandal, and so on and on – a theme with endless variations.